Mock java Questions set - 18

Sun Certified Programmer for the Java 2

Question 1
Given:
11. public interface Status {
12. /* insert code here */ int MY_VALUE = 10;
13. }
Which three are valid on line 12? (Choose three.)
A. final
B. static
C. native
D. public
E. private
F. abstract
G. protected
Answer: ABD
Question 2
Given:
10. public class Bar {
11.static void foo(int...x) {
12. // insert code here
13. }
14. }
Which two code fragments, inserted independently at line 12, will allow
the class to compile? (Choose two.)
A. foreach(x) System.out.println(z);
B. for(int z : x) System.out.println(z);
C. while( x.hasNext()) System.out.println( x.next());
D. for( int i=0; i< x.length; i++ ) System.out.println(x[i]);
Answer: BD
Question 3
Given:
11. public class Test {
12. public static void main(String [] args) {
13. int x =5;
14. boolean b1 = true;
15. boolean b2 = false;
16.
17.if((x==4) && !b2)
18. System.out.print(”l “);
19. System.out.print(”2 “);
20. if ((b2 = true) && b1)
21. System.out.print(”3 “);
22. }
23. }
What is the result?
A. 2
B. 3
C. 1 2
D. 2 3
E. 1 2 3
F. Compilation fails.
G. Au exceptional is thrown at runtime.
Answer: D
Question 4
4. Given:
31. // some code here
32. try {
33. // some code here
34. } catch (SomeException se) {
35. // some code here
36. } finally {
37. // some code here
38. }
Under which three circumstances will the code on line 37 be executed?
(Choose three.)
A. The instance gets garbage collected.
B. The code on line 33 throws an exception.
C. The code on line 35 throws an exception.
D. The code on line 31 throws an exception.
E. The code on line 33 executes successfully.
Answer: BCE
Question 5
Given:
10. interface Foo {}
11. class Alpha implements Foo { }
12. class Beta extends Alpha {}
13. class Delta extends Beta {
14. public static void main( String[] args) {
15. Beta x = new Beta();
16. // insert code here
17. }
18. }
Which code, inserted at line 16, will cause a
java.lang.ClassCastException?
A. Alpha a = x;
B. Foo f= (Delta)x;
C. Foo f= (Alpha)x;
D. Beta b = (Beta)(Alpha)x;
Answer: B
Question 6
Given:
• d is a valid, non-null Date object
• df is a valid, non-null DateFormat object set to the
current locale
What outputs the current locales country name and the appropriate
version of d’s date?
A. Locale loc = Locale.getLocale();
System.out.println(loc.getDisplayCountry()
+ “ “+ df.format(d));
B. Locale loc = Locale.getDefault();
System.out.println(loc.getDisplayCountry()
+ “ “ + df.format(d));
C. Locale bc = Locale.getLocale();
System.out.println(loc.getDisplayCountry()
+ “ “+ df.setDateFormat(d));
D. Locale loc = Locale.getDefault();
System.out.println(loc.getDispbayCountry()
+ “ “+ df.setDateFormat(d));
Answer: B
Question 7
Given:
20. public class CreditCard {
21.
22. private String cardlD;
23. private Integer limit;
24. public String ownerName;
25.
26. public void setCardlnformation(String cardlD,
27. String ownerName,
28. Integer limit) {
29. this.cardlD = cardlD;
30. this.ownerName = ownerName;
31. this.limit = limit;
32. }
33. }
Which is true?
A. The class is fully encapsulated.
B. The code demonstrates polymorphism.
C. The ownerName variable breaks encapsulation.
D. The cardlD and limit variables break polymorphism.
E. The setCardlnformation method breaks encapsulation.
Answer: C
Question 8
Assume that country is set for each class.
Given:
10. public class Money {
11. private String country, name;
12. public getCountry() { return country; }
13.}
and:
24. class Yen extends Money {
25. public String getCountry() { return super.country; }
26. }
27.
28. class Euro extends Money {
29. public String getCountry(String timeZone) {
30. return super.getCountry();
31. }
32. }
Which two are correct? (Choose two.)
A. Yen returns correct values.
B. Euro returns correct values.
C. An exception is thrown at runtime.
D. Yen and Euro both return correct values.
E. Compilation fails because of an error at line 25.
F. Compilation fails because of an error at line 30.
Answer: BE
Question 9
Which Man class properly represents the relationship “Man has a best
friend who is a Dog”?
A. class Man extends Dog { }
B. class Man implements Dog { }
C. class Man { private BestFriend dog; }
D. class Man { private Dog bestFriend; }
E. class Man { private Dog<bestFriend> }
F. class Man { private BestFriend<dog> }
Answer: D
Question 10
Given:
11. public class Person {
12. private name;
13. public Person(String name) {
14. this.name = name;
15. }
16. public int hashCode() {
17. return 420;
18. }
19. }
Which is true?
A. The time to find the value from HashMap with a Person key depends
on the size of the map.
B. Deleting a Person key from a HashMap will delete all map entries for
all keys of type Person.
C. Inserting a second Person object into a HashSet will cause the first
Person object to be removed as a duplicate.
D. The time to determine whether a Person object is contained in a
HashSet is constant and does NOT depend on the size of the map.
Answer: A
Question 11
Given:
23. Object [] myObjects = {
24. new integer(12),
25. new String(”foo”),
26. new integer(5),
27. new Boolean(true)
28. };
29. Arrays.sort(myObjects);
30. for( int i=0; i<myObjects.length; i++) {
31. System.out.print(myObjects[i].toString());
32. System.out.print(” “);
33. }
What is the result?
A. Compilation fails due to an error in line 23.
B. Compilation fails due to an error in line 29.
C. A ClassCastException occurs in line 29.
D. A ClassCastException occurs in line 31.
E. The value of all four objects prints in natural order.
Answer: C
Question 12
12. Given:
13. public class Pass {
14. public static void main(String [1 args) {
15. int x 5;
16. Pass p = new Pass();
17. p.doStuff(x);
18. System.out.print(” main x = “+ x);
19. }
20.
21. void doStuff(int x) {
22. System.out.print(” doStuff x = “+ x++);
23. }
24. }
What is the result?
A. Compilation fails.
B. An exception is thrown at runtime.
C. doStuffx = 6 main x = 6
D. doStuffx = 5 main x = 5
E. doStuffx = 5 main x = 6
F. doStuffx = 6 main x = 5
Answer: D
Question 13
Given:
10. package com.sun.scjp;
11. public class Geodetics {
12. public static final double DIAMETER = 12756.32; // kilometers
13. }
Which two correctly access the DIAMETER member of the Geodetics
class? (Choose two.)
A. import com.sun.scjp.Geodetics;
public class TerraCarta {
public double halfway()
{ return Geodetics.DIAMETER/2.0; } }
B. import static com.sun.scjp.Geodetics;
public class TerraCarta {
public double halfway() { return DIAMETER/2.0; } }
C. import static com.sun.scjp.Geodetics. *;
public class TerraCarta {
public double halfway() { return DIAMETER/2.0; } }
D. package com.sun.scjp;
public class TerraCarta {
public double halfway() { return DIAMETER/2.0; } }
Answer: AC
Question 14
Given:
10. class Nav{
11. public enum Direction { NORTH, SOUTH, EAST, WEST }
12. }
13. public class Sprite{
14. // insert code here
15. }
Which code, inserted at line 14, allows the Sprite class to compile?
A. Direction d = NORTH;
B. Nav.Direction d = NORTH;
C. Direction d = Direction.NORTH;
D. Nav.Direction d = Nav.Direction.NORTH;
Answer: D
Question 15
Given:
10. interface Foo { int bar(); }
11. public class Sprite {
12. public int fubar( Foo foo) { return foo.bar(); }
13. public void testFoo() {
14. fubar(
15. // insert code here
16.);
17. }
18. }
Which code, inserted at line 15, allows the class Sprite to compile?
A. Foo { public int bar() { return 1; } }
B. new Foo { public int bar() { return 1; } }
C. newFoo() { public int bar(){return 1; } }
D. new class Foo { public int bar() { return 1; } }
Answer: C
Question 16
Click the Exhibit button.
10. interface Foo {
11. int bar();
12. }
13.
14. public class Beta {
15.
16. class A implements Foo {
17. public int bar() { return 1; }
18. }
19.
20. public int fubar( Foo foo) { return foo.bar(); }
21.
22. public void testFoo() {
23.
24. class A implements Foo {
25. public int bar() { return 2; }
26. }
27.
28. System.out.println( fubar( new A()));
29. }
30.
31. public static void main( String[] argv) {
32. new Beta().testFoo();
33. }
34. }
Which three statements are true? (Choose three.)
A. Compilation fails.
B. The code compiles and the output is 2.
C. If lines 16, 17 and 18 were removed, compilation would fail.
D. If lines 24, 25 and 26 were removed, compilation would fail.
E. If lines 16, 17 and 18 were removed, the code would compile and
the output would be 2.
F. If lines 24, 25 and 26 were removed, the code would compile and
the output would be 1.
Answer: BEF
Question 17
Given:
1. package sun.scjp;
2. public enum Color { RED, GREEN, BLUE }
1. package sun.beta;
2. // insert code here
3. public class Beta {
4. Color g = GREEN;
5. public static void main( String[] argv)
6. { System.out.println( GREEN); }
7. }
The class Beta and the enum Color are in different packages.
Which two code fragments, inserted individually at line 2 of the Beta
declaration, will allow this code to compile? (Choose two.)
A. import sun.scjp.Color.*;
B. import static sun.scjp.Color.*;
C. import sun.scjp.Color; import static sun.scjp.Color.*;
D. import sun.scjp.*; import static sun.scjp.Color.*;
E. import sun.scjp.Color; import static sun.scjp.Color.GREEN;
Answer: CE
Question 18
Given:
1. public interface A {
2. String DEFAULT_GREETING = “Hello World”;
3. public void method1();
4. }
A programmer wants to create an interface called B that has A as its
parent. Which interface declaration is correct?
A. public interface B extends A { }
B. public interface B implements A {}
C. public interface B instanceOf A {}
D. public interface B inheritsFrom A { }
Answer: A
Question 19
Given:
1. class TestA {
2. public void start() { System.out.println(”TestA”); }
3. }
4. public class TestB extends TestA {
5. public void start() { System.out.println(”TestB”); }
6. public static void main(String[] args) {
7. ((TestA)new TestB()).start();
8. }
9. }
What is the result?
A. TestA
B. TestB
C. Compilation fails.
D. An exception is thrown at runtime.
Answer: B
Question 20
Given:
1. interface TestA { String toString(); }
2. public class Test {
3. public static void main(String[] args) {
4. System.out.println(new TestA() {
5. public String toString() { return “test”; }
6. });
7. }
8. }
What is the result?
A. test
B. null
C. An exception is thrown at runtime.
D. Compilation fails because of an error in line 1.
E. Compilation fails because of an error in line 4.
F. Compilation fails because of an error in line 5.
Answer: A
Question 21
Given:
11. public abstract class Shape {
12. int x;
13. int y;
14. public abstract void draw();
15. public void setAnchor(int x, int y) {
16. this.x = x;
17. this.y = y;
18. }
19. }
and a class Circle that extends and fully implements the Shape class.
Which is correct?
A. Shape s = new Shape();
s.setAnchor(10,10);
s.draw();
B. Circle c = new Shape();
c.setAnchor(10,10);
c.draw();
C. Shape s = new Circle();
s.setAnchor(10,10);
s.draw();
D. Shape s = new Circle();
s->setAnchor(10,10);
s->draw();
E. Circle c = new Circle();
c.Shape.setAnchor(10,10);
c.Shape.draw();
Answer: C
Question 22
Given:
10. abstract public class Employee {
11. protected abstract double getSalesAmount();
12. public double getCommision() {
13. return getSalesAmount() * 0.15;
14. }
15. }
16. class Sales extends Employee {
17. // insert method here
18. }
Which two methods, inserted independently at line 17, correctly
complete the Sales class? (Choose two.)
A. double getSalesAmount() { return 1230.45; }
B. public double getSalesAmount() { return 1230.45; }
C. private double getSalesAmount() { return 1230.45; }
D. protected double getSalesAmount() { return 1230.45; }
Answer: BD
Question 23
Given:
10. interface Data { public void load(); }
11. abstract class Info { public abstract void load(); }
Which class correctly uses the Data interface and Info class?
A. public class Employee extends Info implements Data {
public void load() { /*do something*/ }
}
B. public class Employee implements Info extends Data {
public void load() { /*do something*/ }
}
C. public class Employee extends Info implements Data {
public void load() { /*do something */ }
public void Info.load() { /*do something*/ }
}
D. public class Employee implements Info extends Data {
public void Data.load() { /*d something */ }
public void load() { /*do something */ }
}
E. public class Employee implements Info extends Data {
public void load() { /*do something */ }
public void Info.load(){ /*do something*/ }
}
F. public class Employee extends Info implements Data{
public void Data.load() { /*do something*/ }
public void Info.load() { /*do something*/ }
}
Answer: A
Question 24
Given:
11. public abstract class Shape {
12. private int x;
13. private int y;
14. public abstract void draw();
15. public void setAnchor(int x, int y) {
16. this.x = x;
17. this.y = y;
18. }
19. }
Which two classes use the Shape class correctly? (Choose two.)
A. public class Circle implements Shape {
private int radius;
}
B. public abstract class Circle extends Shape {
private int radius;
}
C. public class Circle extends Shape {
private int radius;
public void draw();
}
D. public abstract class Circle implements Shape {
private int radius;
public void draw();
}
E. public class Circle extends Shape {
private int radius;
public void draw() {/* code here */}
}
F. public abstract class Circle implements Shape {
private int radius;
public void draw() { / code here */ }
}
Answer: BE
Question 25
Which two classes correctly implement both the java.lang.Runnable
and the java.lang.Clonable interfaces? (Choose two.)
A. public class Session
implements Runnable, Clonable {
public void run();
public Object clone();
}
B. public class Session
extends Runnable, Clonable {
public void run() { / do something */ }
public Object clone() { / make a copy */ }
}
C. public class Session
implements Runnable, Clonable {
public void run() { / do something */ }
public Object clone() { /* make a copy */ }
}
D. public abstract class Session
implements Runnable, Clonable {
public void run() { / do something */ }
public Object clone() { /*make a copy */ }
}
E. public class Session
implements Runnable, implements Clonable {
public void run() { / do something */ }
public Object clone() { / make a copy */ }
}
Answer: CD
Question26
Click the Exhibit button.
1. public class GoTest {
2. public static void main(String[] args) {
3. Sente a = new Sente(); a.go();
4. Goban b = new Goban(); b.go();
5. Stone c = new Stone(); c.go();
6. }
7. }
8.
9. class Sente implements Go {
10. public void go() { System.out.println(”go in Sente.”); }
11. }
12.
13. class Goban extends Sente {
14. public void go() { System.out.println(”go in Goban”); }
15. }
16.
17. class Stone extends Goban implements Go { }
18.
19. interface Go { public void go(); }
What is the result?
A. go in Goban
go in Sente
go in Sente
B. go in Sente
go in Sente
go in Goban
C. go in Sente
go in Goban
go in Goban
D. go in Goban
go in Goban
go in Sente
E. Compilation fails because of an error in line 17.
Answer: C
Question 27
Given:
11. public static void parse(String str) {
12. try {
13. float f= Float.parseFloat(str);
14. } catch (NumberFormatException nfe) {
15. f= 0;
16. } finally {
17. System.out.println(f);
18. }
19. }
20. public static void main(String[] args) {
21. parse(”invalid”);
22. }
What is the result?
A. 0.0
B. Compilation fails.
C. A ParseException is thrown by the parse method at runtime.
D. A NumberFormatException is thrown by the parse method at
runtime.
Answer: B
Question 28
Click the Exhibit button.
1. public class Test {
2. int x= 12;
3. public void method(int x) {
4. x+=x;
5. System.out.println(x);
6. }
7. }
Given:
34. Test t = new Test();
35. t.method(5);
What is the output from line 5 of the Test class?
A. 5
B. 10
C. 12
D. 17
E. 24
Answer: B
Question 28
Given:
55. int []x= {1, 2,3,4, 5};
56.int y[] =x;
57. System.out.println(y[2]);
Which is true?
A. Line 57 will print the value 2.
B. Line 57 will print the value 3.
C. Compilation will fail because of an error in line 55.
D. Compilation will fail because of an error in line 56.
Answer: B
Question 30
Given:
35. String #name = “Jane Doe”;
36.int$age=24;
37. Double_height = 123.5;
38. double~temp = 37.5;
Which two are true? (Choose two.)
A. Line 35 will not compile.
B. Line 36 will not compile.
C. Line 37 will not compile.
D. Line 38 will not compile.
Answer: AD
Question 31
Which two code fragments correctly create and initialize a static array
of int elements? (Choose two.)
A. static final int[] a = { 100,200 };
B. static final int[] a;
static { a=new int[2]; a[0]=100; a[1]=200; }
C. static final int[] a = new int[2] { 100,200 };
D. static final int[] a;
static void init() { a = new int[3]; a[0]=100; a[1]=200; }
Answer: AB
Question 32
Given:
11. public class Ball {
12. public enum Color { RED, GREEN, BLUE };
13. public void foo() {
14. // insert code here
15. { System.out.println(c); }
16. }
17. }
Which code inserted at line 14 causes the foo method to print RED,
GREEN, and BLUE?
A. for( Color c : Color.values())
B. for( Color c = RED; c <= BLUE; c++)
C. for( Color c; c.hasNext() ; c.next())
D. for( Color c = Color[0]; c <= Color[2]; c++)
E. for( Color c = Color.RED; c <= Color.BLUE; c++)
Answer: A
Question 33
Given:
10. public class Fabric
11. public enum Color {
12. RED(0xff0000), GREEN(0x00ff00), BLUE(0x0000ff);
13. private final int rgb;
14. Color( int rgb) { this.rgb = rgb; }
15. public int getRGB() { return rgb; }
16. };
17. public static void main( String[] argv) {
18. // insert code here
19. }
20. }
Which two code fragments, inserted independently at line 18, allow the
Fabric class to compile? (Choose two.)
A. Color skyColor = BLUE;
B. Color treeColor = Color.GREEN;
C. Color purple = new Color( 0xff00ff);
D. if( RED.getRGB() < BLUE.getRGB() ) {}
E. Color purple = Color.BLUE + Color.RED;
F. if( Color.RED.ordinal() < Color.BLUE.ordinal() ) {}
Answer: BF
Question 34
Given:
11. public enum Title {
12. MR(”Mr.”), MRS(”Mrs.”), MS(”Ms.”);
13. private final String title;
14. private Title(String t) { title = t; }
15. public String format(String last, String first) {
16. return title + “ “ + first + “ “ + last;
17. }
18. }
19. public static void main(String[] args) {
20. System.out.println(Title.MR.format(”Doe”, “John”));
21. }
What is the result?
A. Mr. John Doe
B. An exception is thrown at runtime.
C. Compilation fails because of an error in line 12.
D. Compilation fails because of an error in line 15.
E. Compilation fails because of an error in line 20.
Answer: A
Question 35
Given:
11. public static void main(String[] args) {
12. Object obj =new int[] { 1,2,3 };
13. int[] someArray = (int[])obj;
14. for (int i: someArray) System.out.print(i +“ “)
15. }
‘What is the result?
A. 1 2 3
B. Compilation fails because of an error in line 12.
C. Compilation fails because of an error in line 13.
D. Compilation fails because of an error in line 14.
E. A ClassCastException is thrown at runtime.
Answer: A
Question 36
Given:
10. class Foo {
11. static void alpha() { /* more code here */ }
12. void beta() { /* more code here */ }
13. }
Which two are true? (Choose two.)
A. Foo.beta() is a valid invocation of beta().
B. Foo.alpha() is a valid invocation of alpha().
C. Method beta() can directly call method alpha().
D. Method alpha() can directly call method beta().
Answer: BC
Question 37
A programmer needs to create a logging method that can accept an
arbitrary number of arguments. For example, it may be called in these
ways:
logIt(”log message 1 “);
logIt(”log message2”,”log message3”);
logIt(”log message4”, “log message5”, “log message6);
Which declaration satisfies this requirement?
A. public void logIt(String * msgs)
B. public void logIt(String [] msgs)
C. public void logIt(String... msgs)
D. public void logIt(String msg1, String msg2, String msg3)
Answer: C
Question 38
A programmer is designing a class to encapsulate the information
about an inventory item. A JavaBeans component is needed to
do this. The Inventoryltem class has private instance variables to store
the item information:
10. private int itemId;
11. private String name;
12. private String description;
Which method signature follows the JavaBeans naming standards for
modifying the itemld instance variable?
A. itemID(int itemId)
B. update(int itemId)
C. setItemId(int itemId)
D. mutateItemId(int itemId)
E. updateItemID(int itemId)
Answer: C
Question 39
Click the Exhibit button.
1. public class A {
2.
3. private int counter = 0;
4.
5. public static int getInstanceCount() {
6. return counter;
7. }
8.
9. public A() {
10. counter++;
11. }
12.
13. }
Given this code from Class B:
25.A a1 =new A();
26. A a2 =new A();
27. A a3 =new A();
28. System.out.printIn(A.getInstanceCount() );
What is the result?
A. Compilation of class A fails.
B. Line 28 prints the value 3 to System.out.
C. Line 28 prints the value 1 to System.out.
D. A runtime error occurs when line 25 executes.
E. Compilation fails because of an error on line 28.
Answer: A
Question 40
A JavaBeans component has the following field:
11. private boolean enabled;
Which two pairs of method declarations follow the JavaBeans standard
for accessing this field? (Choose two.)
A. public void setEnabled( boolean enabled)
public boolean getEnabled()
B. public void setEnabled( boolean enabled)
public void isEnabled()
C. public void setEnabled( boolean enabled)
public boolean isEnabled()
D. public boolean setEnabled( boolean enabled)
public boolean getEnabled()
Answer: AC
Question 41
41. Given:
10. class One {
11. public One foo() { return this; }
12. }
13. class Two extends One {
14. public One foo() { return this; }
15. }
16. class Three extends Two {
17. // insert method here
18. }
Which two methods, inserted individually, correctly complete the Three
class? (Choose two.)
A. public void foo() { }
B. public int foo() { return 3; }
C. public Two foo() { return this; }
D. public One foo() { return this; }
E. public Object foo() { return this; }
Answer: CD
Question 42
Given:
10. class One {
11. void foo() {}
12. }
13. class Two extends One {
14. //insert method here
15. }
Which three methods, inserted individually at line 14, will correctly
complete class Two? (Choose three.)
A. int foo() { /* more code here */ }
B. void foo() { /* more code here */ }
C. public void foo() { /* more code here */ }
D. private void foo() { /* more code here */ }
E. protected void foo() { /* more code here */ }
Answer: BCE
Question 43
Click the Exhibit button.
1. public interface A {
2. public void doSomething(String thing);
3. }
1. public class AImpl implements A {
2. public void doSomething(String msg) { }
3. }
1. public class B {
2. public A doit() {
3. // more code here
4. }
5.
6. public String execute() {
7. // more code here
8. }
9. }
1. public class C extends B {
2. public AImpl doit() {
3. // more code here
4. }
5.
6. public Object execute() {
7. // more code here
8. }
9. }
Which statement is true about the classes and interfaces in the
exhibit?
A. Compilation will succeed for all classes and interfaces.
B. Compilation of class C will fail because of an error in line 2.
C. Compilation of class C will fail because of an error in line 6.
D. Compilation of class AImpl will fail because of an error in line 2.
Answer: C
Question 44
Click the Exhibit button.
1. public class A {
2. public String doit(int x, int y) {
3. return “a”;
4. }
5.
6. public String doit(int... vals) {
7. return “b”;
8. }
9. }
Given:
25. A a=new A();
26. System.out.println(a.doit(4, 5));
What is the result?
A. Line 26 prints “a” to System.out.
B. Line 26 prints ‘b” to System.out.
C. An exception is thrown at line 26 at runtime.
D. Compilation of class A will fail due to an error in line 6.
Answer: A
Question 45
Given:
1. public class A {
2. public void doit() {
3. }
4. public String doit() {
5. return “a”;
6. }
7. public double doit(int x) {
8. return 1.0;
9. }
10.}
What is the result?
A. An exception is thrown at runtime.
B. Compilation fails because of an error in line 7.
C. Compilation fails because of an error in line 4.
D. Compilation succeeds and no runtime errors with class A occur.
Answer: C
Question 46
46. Given:
10. class Line {
11. public static class Point { }
12. }
13.
14. class Triangle {
15. // insert code here
16. }
Which code, inserted at line 15, creates an instance of the Point class
defined in Line?
A. Point p = new Point();
B. Line.Point p = new Line.Point();
C. The Point class cannot be instatiated at line 15.
D. Line 1 = new Line() ; 1.Point p = new 1.Point();
Answer: B
Question 47
Given:
10. class Line {
11. public class Point { public int x,y; }
12. public Point getPoint() { return new Point(); }
13. }
14. class Triangle {
15. public Triangle() {
16. // insert code here
17. }
18. }
Which code, inserted at line 16, correctly retrieves a local instance of a
Point object?
A. Point p = Line.getPoint();
B. Line.Point p = Line.getPoint();
C. Point p = (new Line()).getPoint();
D. Line.Point p = (new Line()).getPoint();
Answer: D
Question 48
Given:
10. class One {
11. public One() { System.out.print(1); }
12. }
13. class Two extends One {
14. public Two() { System.out.print(2); }
15. }
16. class Three extends Two {
17. public Three() { System.out.print(3); }
18. }
19. public class Numbers{
20. public static void main( String[] argv) { new Three(); }
21. }
What is the result when this code is executed?
A. 1
B. 3
C. 123
D. 321
E. The code rims with no output.
Answer: C
Question 49
Click the Exhibit button.
11. class Person {
12. String name = “No name’;
13. public Person(String nm) { name = nm; }
14. }
15.
16. class Employee extends Person {
17. String emplD = “0000”;
18. public Employee(String id) { empID = id; }
19. }
20.
21. public class EmployeeTest {
22. public static void main(String[] args) {
23. Employee e = new Employee(”4321”);
24. System.out.println(e.empID);
25. }
26. }
What is the result?
A. 4321
B. 0000
C. An exception is thrown at runtime.
D. Compilation fails because of an error in line 18.
Answer: D
Question 50
Given:
1. public class Plant {
2. private String name;
3. public Plant(String name) { this.name = name; }
4. public String getName() { return name; }
5. }
1. public class Tree extends Plant {
2. public void growFruit() { }
3. public void dropLeaves() { }
4. }
Which is true?
A. The code will compile without changes.
B. The code will compile if public Tree() { Plant(); } is added to the
Tree class.
C. The code will compile if public Plant() { Tree(); } is added to the
Plant class.
D. The code will compile if public Plant() { this(”fern”); } is added to
the Plant class.
E. The code will compile if public Plant() { Plant(”fern”); } is added to
the Plant class.
Answer: D
Question 51
Click the Exhibit button.
11. public class Bootchy {
12. int bootch;
13. String snootch;
14.
15. public Bootchy() {
16. this(”snootchy”);
17. System.out.print(”first “);
18. }
19.
20. public Bootchy(String snootch) {
21. this(420, “snootchy”);
22. System.out.print(”second “);
23. }
24.
25. public Bootchy(int bootch, String snootch) {
26. this.bootch = bootch;
27. this.snootch = snootch;
28. System.out.print(”third “);
29. }
30.
31. public static void main(String[] args) {
32. Bootchy b = new Bootchy();
33. System.out.print(b.snootch +“ “ + b.bootch);
34. }
35. }
What is the result?
A. snootchy 420 third second first
B. snootchy 420 first second third
C. first second third snootchy 420
D. third second first siiootchy 420
E. third first second snootchy 420
F. first second first third snootchy 420
Answer: D
Question 52
Given:
11. public class Test {
12. public enum Dogs {collie, harrier, shepherd};
13. public static void main(String [] args) {
14. Dogs myDog = Dogs.shepherd;
15. switch (myDog) {
16. case collie:
17. System.out.print(”collie “);
18. case default:
19. System.out.print(”retriever “);
20. case harrier:
21. System.out.print(”harrier “);
22. }
23. }
24. }
‘What is the result?
A. harrier
B. shepherd
C. retriever
D. Compilation fails.
E. retriever harrier
F. An exception is thrown at runtime.
Answer: D
Question 53
Given:
12. public class Test {
13. public enum Dogs {collie, harrier};
14. public static void main(String [] args) {
15. Dogs myDog = Dogs.collie;
16. switch (myDog) {
17. case collie:
18. System.out.print(”collie “);
19. case harrier:
20. System.out.print(”harrier “);
21. }
22. }
23. }
What is the result?
A. collie
B. harrier
C. Compilation fails.
D. collie harrier
E. An exception is thrown at runtime.
Answer: D
Question 54
Given:
11. public void testIfA() {
12. if(testIfB(”True”)) {
13. System.out.println(”True”);
14. } else {
15. System.out.println(”Not true”);
16. }
17. }
18. public Boolean testIfB(String str) {
19. return Boolean.valueOf(str);
20. }
What is the result when method testIfA is invoked?
A. True
B. Not true
C. An exception is thrown at runtime.
D. Compilation fails because of an error at line 12.
E. Compilation fails because of an error at line 19.
Answer: A
Question 55
Given:
11. public static void main(String[] args) {
12. Integer i = uew Integer(1) + new Integer(2);
13. switch(i) {
14. case 3: System.out.println(”three”); break;
15. default: System.out.println(”other”); break;
16. }
17. }
‘What is the result?
A. three
B. other
C. An exception is thrown at runtime.
D. Compilation fails because of an error on line 12.
E. Compilation fails because of an error on line 13.
F. Compilation fails because of an error on line 15.
Answer: A
Question 56
Given:
11. public static void main(String[] args) {
12. String str = “null’;
13. if (str == null) {
14. System.out.println(”null”);
15. } else (str.length() == 0) {
16. System.out.println(”zero”);
17. } else {
18. System.out.println(”some”);
19. }
20. }
‘What is the result?
A. null
B. zero
C. some
D. Compilation fails.
E. An exception is thrown at runtime.
Answer: D
Question 57
Given:
11. Float pi = new Float(3.14f);
12.if(pi>3) {
13. System.out.print(”pi is bigger than 3. “);
14. }
15. else {
16. System.out.print(”pi is not bigger than 3. “);
17. }
18. finally {
19. System.out.println(”Have a nice day.”);
20. }
‘What is the result?
A. Compilation fails.
B. pi is bigger than 3.
C. An exception occurs at runtime.
D. pi is bigger than 3. Have a nice day.
E. pi is not bigger than 3. Have a nice day.
Answer: A
Question 58
Given:
10.int x=0;
11.int y 10;
12. do {
l3. y--;
14. ++x;
15. } while (x < 5);
16. System.out.print(x + “,“ + y);
What is the result?
A. 5,6
B. 5,5
C. 6,5
D. 6,6
Answer: B
Question 59
Given:
25.intx=12;
26. while (x < 10) {
27. x--;
28. }
29. System.out.print(x);
What is the result?
A. 0
B. 10
C. 12
D. Line 29 will never be reached.
Answer: C
Question 60
Given:
35. int x= 10;
36. do {
37. x--;
38. } while(x< 10);
How many times will line 37 be executed?
A. ten times
B. zero times
C. one to me times
D. more than ten times
Answer: D
Question 61
Give:
11. public static Iterator reverse(List list) {
12. Collections.reverse(list);
13. return list.iterator();
14. }
15. public static void main(String[] args) {
16. List list = new ArrayList();
17. list.add(” 1”); list.add(”2”); list.add(”3”);
18. for (Object obj: reverse(list))
19. System.out.print(obj + “,”);
20. }
‘What is the result?
A. 3,2, 1,
B. 1, 2, 3,
C. Compilation fails.
D. The code runs with no output.
E. An exception is thrown at runtime.
Answer: C
Question 62
Given:
11. public static Collection get() {
12. Collection sorted = new LinkedList();
13. sorted.add(’B”); sorted.add(”C”); sorted.add(”A”);
14. return sorted;
15. }
16. public static void main(String[] args) {
17. for (Object obj: get()) {
18. System.out.print(obj + “, “);
19. }
20. }
What is the result?
A. A, B, C,
B. B, C, A,
C. Compilation fails.
D. The code runs with no output.
E. An exception is thrown at runtime.
Answer: B
Question 63
Given:
11. public static void main(String[] args) {
12. for (int i=0;i<= 10;i++){
13. if( i>6) break;
14. }
15. System.out.println(i);
16. }
What is the result?
A. 6
B. 7
C. 10
D. 11
E. Compilation fails.
F. An exception is thrown at runtime.
Answer: E
Question 64
Given:
8. public class test {
9. public static void main(String [] a) {
10. assert a.length == 1;
11. }
12. }
Which two will produce an AssertionError? (Choose two.)
A. java test
B. java -ea test
C. java test file1
D. java -ea test file1
E. java -ea test file1 file2
F. java -ea:test test file1
Answer: BE
Question 65
Given:
12. public class AssertStuff {
13.
14. public static void main(String [] args) {
15. int x= 5;
16. int y= 7;
17.
18. assert (x> y): “stuff”;
19. System.out.println(”passed”);
20. }
21. }
And these command line invocations:
java AssertStuff
java -ea AssertStuff
What is the result?
A. passed
stuff
B. stuff
passed
C. passed
An AssertionError is thrown with the word “stuff” added to the stack
trace.
D. passed
An AssertionError is thrown without the word “stuff” added to the
stack trace.
E. passed
An AssertionException is thrown with the word “stuff” added to the
stack trace.
F. passed
An AssertionException is thrown without the word “stuff” added to the
stack trace.
Answer: C
Question 66
Click the Exhibit button.
1. public class Test {
2.
3. public static void main(String [] args) {
4. boolean assert = true;
5. if(assert) {
6. System.out.println(”assert is true”);
7. }
8. }
9.
10. }
Given:
javac -source 1.3 Test.java
What is the result?
A. Compilation fails.
B. Compilation succeeds with errors.
C. Compilation succeeds with warnings.
D. Compilation succeeds without warnings or errors.
Answer: C
Question 67
Given:
23.int z=5;
24.
25. public void stuff1(int x) {
26. assert (x> 0);
27. switch(x) {
28. case 2: x= 3;
29. default: assert false; } }
30.
31. private void stuff2(int y) { assert (y < 0); }
32.
33. private void stuff3() { assert (stuff4O); }
34.
35. private boolean stuff4() { z = 6; return false; }
Which is true?
A. All of the assert statements are used appropriately.
B. Only the assert statement on line 31 is used appropriately.
C. The assert statements on lines 29 and 31 are used appropriately.
D. The assert statements on lines 26 and 29 are used appropriately.
E. The assert statements on lines 29 and 33 are used appropriately.
F. The assert statements on lines 29, 31, and 33 are used
appropriately.
G. The assert statements on lines 26, 29, and 31 are used
appropriately.
Answer: C
Question 68
Click the Exhibit button.
SomeException:
1. public class SomeException {
2. }
Class A:
1. public class A {
2. public void doSomething() { }
3. }
Class B:
1. public class B extends A {
2. public void doSomething() throws SomeException { }
3. }
Which is true about the two classes?
A. Compilation of both classes will fail.
B. Compilation of both classes will succeed.
C. Compilation of class A will fail. Compilation of class B will succeed.
D. Compilation of class B will fail. Compilation of class A will succeed.
Answer: D
Question 69
Click the Exhibit button.
Class TestException
1. public class TestException extends Exception {
2. }
Class A:
1. public class A {
2.
3. public String sayHello(String name) throws TestException {
4.
5. if(name == null) {
6. throw new TestException();
7. }
8.
9. return “Hello “+ name;
10. }
11.
12. }
A programmer wants to use this code in an application:
45. A a=new A();
46. System.out.println(a.sayHello(”John”));
Which two are true? (Choose two.)
A. Class A will not compile.
B. Line 46 can throw the unchecked exception TestException.
C. Line 45 can throw the unchecked exception TestException.
D. Line 46 will compile if the enclosing method throws a TestException.
E. Line 46 will compile if enclosed in a try block, where TestException
is caught.
Answer: DE
Question 70
Given:
33. try {
34. // some code here
35. } catch (NullPointerException e1) {
36. System.out.print(”a”);
37. } catch (RuntimeException e2) {
38. System.out.print(”b”);
39. } finally {
40. System.out.print(”c”);
41. }
What is the result if a NullPointerException occurs on line 34?
A. c
B. a
C. ab
D. ac
E. bc
F. abc
Answer: D
Question 71
Given:
11.classA {
12. public void process() { System.out.print(”A,”); } }
13. class B extends A {
14. public void process() throws IOException {
15. super.process();
16. System.out.print(”B,”);
17. throw new IOException();
18. } }
19. public static void main(String[] args) {
20. try { new B().process(); }
21. catch (IOException e) { System.out.println(”Exception”); } }
What is the result?
A. Exception
B. A,B,Exception
C. Compilation fails because of an error in line 20.
D. Compilation fails because of an error in line 14.
E. A NullPointerException is thrown at runtime.
Answer: D
Question 72
Given:
11.classA {
12. public void process() { System.out.print(”A “); } }
13. class B extends A {
14. public void process() throws RuntimeException {
15. super.process();
16. if (true) throw new RuntimeException();
17. System.out.print(“B”); }}
18. public static void main(String[] args) {
19. try { ((A)new B()).process(); }
20. catch (Exception e) { System.out.print(”Exception “); }
21. }
What is the result?
A. Exception
B. A Exception
C. A Exception B
D. A B Exception
E. Compilation fails because of an error in line 14.
F. Compilation fails because of an error in line 19.
Answer: B
Question 73
Given:
11. static classA {
12. void process() throws Exception { throw new Exception(); }
13. }
14. static class B extends A {
15. void process() { System.out.println(”B “); }
16. }
17. public static void main(String[] args) {
18.A a=new B();
19. a.process();
20.}
What is the result?
A. B
B. The code runs with no output.
C. An exception is thrown at runtime.
D. Compilation fails because of an error in line 15.
E. Compilation fails because of an error in line 18.
F. Compilation fails because of an error in line 19.
Answer: F
Question 74
Given:
11. static class A {
12. void process() throws Exception { throw new Exception(); }
13. }
14. static class B extends A {
15. void process() { System.out.println(”B”); }
16. }
17. public static void main(String[] args) {
18. new B().process();
19. }
What is the result?
A. B
B. The code runs with no output.
C. Compilation fails because of an error in line 12.
D. Compilation fails because of an error in line 15.
E. Compilation fails because of an error in line 18.
Answer: A
Question 75
Given:
84. try {
85. ResourceConnection con = resourceFactory.getConnection();
86. Results r = con.query(”GET INFO FROM CUSTOMER”);
87. info = r.getData();
88. con.close();
89. } catch (ResourceException re) {
90. errorLog.write(re.getMessage());
91. }
92. return info;
Which is true if a ResourceException is thrown on line 86?
A. Line 92 will not execute.
B. The connection will not be retrieved in line 85.
C. The resource connection will not be closed on line 88.
D. The enclosing method will throw an exception to its caller.
Answer: C
Question 76
Click the Exhibit button.
1. public class A {
2. public void method1() {
3. B b=new B();
4. b.method2();
5. // more code here
6. }
7. }
1. public class B {
2. public void method2() {
3.C c=new C();
4. c.method3();
5. // more code here
6. }
7. }
1. public class C {
2. public void method3() {
3. // more code here
4. }
5. }
Given:
25. try {
26. A a=new A();
27. a.method1();
28. } catch (Exception e) {
29. System.out.print(”an error occurred”);
30. }
Which two are true if a NullPointerException is thrown on line 3 of
class C? (Choose two.)
A. The application will crash.
B. The code on line 29 will be executed.
C. The code on line 5 of class A will execute.
D. The code on line 5 of class B will execute.
E. The exception will be propagated back to line 27.
Answer: BE
Question 77
Click the Exhibit button.
1. public class A {
2. public void method1() {
3. try {
4. B b=new B();
5. b.method2();
6. // more code here
7. } catch (TestException te) {
8. throw new RuntimeException(te);
9. }
6. }
7. }
1. public class B {
2. public void method2() throws TestException {
3. // more code here
4. }
5. }
1. public class TestException extends Exception {
2. }
Given:
31. public void method() {
32. A a=new A();
33. a.method1();
34. }
Which is true if a TestException is thrown on line 3 of class B?
A. Line 33 must be called within a try block.
B. The exception thrown by method1 in class A is not required to be
caught.
C. The method declared on line 31 must be declared to throw a
RuntimeException.
D. On line 5 of class A, the call to method2 of class B does not need to
be placed in a try/catch block.
Answer: B
Question 78
Given:
11. public static void main(String[] args) {
12. try {
13. args=null;
14. args[0] = “test”;
15. System.out.println(args[0]);
16. } catch (Exception ex) {
17. System.out.println(”Exception”);
18. } catch (NullPointerException npe) {
19. System.out.println(”NullPointerException”);
20. }
21. }
What is the result?
A. test
B. Exception
C. Compilation fails.
D. NullPointerException
Answer: C
Question 79
Given:
11. static void test() throws Error {
12. if (true) throw new AssertionError();
13. System.out.print(”test “);
14. }
15. public static void main(String[] args) {
16. try { test(); }
17. catch (Exception ex) { System.out.print(”exception “); }
18. System.out.print(”elld “);
19. }
What is the result?
A. end
B. Compilation fails.
C. exception end
D. exception test end
E. A Throwable is thrown by main.
F. An Exception is thrown by main.
Answer: E
Question 80
Given:
11. static void test() {
12. try {
13. String x=null;
14. System.out.print(x.toString() +“ “);
15. }
16. finally { System.out.print(“finally “); }
17. }
18. public static void main(String[] args) {
19. try { test(); }
20. catch (Exception ex) { System.out.print(”exception “); }
21. }
What is the result?
A. null
B. finally
C. null finally
D. Compilation fails.
E. finally exception
Answer: E
Question 81
Given:
11. static void test() throws RuntimeException {
12. try {
13. System.out.print(”test “);
14. throw new RuntimeException();
15. }
16. catch (Exception ex) { System.out.print(”exception “); }
17. }
18. public static void main(String[] args) {
19. try { test(); }
20. catch (RuntimeException ex) { System.out.print(”runtime “); }
21. System.out.print(”end “);
22. }
What is the result?
A. test end
B. Compilation fails.
C. test runtime end
D. test exception end
E. A Throwable is thrown by main at runtime.
Answer: D
Question 82
Given a method that must ensue that its parameter is not null:
11. public void someMethod(Object value) {
12. // check for null value
....
20. System.out.println(value.getClass());
21. }
What, inserted at line 12, is the appropriate way to handle a null
value?
A. assert value == null;
B. assert value !null, “value is null”;
C. if (value == null) {
throw new AssertionException(”value is null”);
D. if (value == null) {
throw new IllegalArgumentException(”value is null”);
Answer: D
Question 83
Click the Exhibit button.
10. public class ClassA {
11. public void methodA() {
12. ClassB classB = new ClassB();
13. classB.getValue();
14. }
15. }
And:
20. class ClassB {
21. public ClassC classC;
22.
23. public String getValue() {
24. return classC.getValue();
25. }
26. }
And:
30. class ClassC {
31. public String value;
32.
33. public String getValue() {
34. value = “ClassB”;
35. return value;
36. }
37. }
Given:
ClassA a = new ClassA();
a.methodA();
What is the result?
A. Compilation fails.
B. ClassC is displayed.
C. The code runs with no output.
D. An exception is thrown at runtime.
Answer: D
Question 84
Given:
10. public class Foo {
11. static int[] a;
12. static { a[0]=2; }
13. public static void main( String[] args) {}
14. }
Which exception or error will be thrown when a programmer attempts
to run this code?
A. java.lang. StackOverflowError
B. java.lang.IllegalStateException
C. java.lang.ExceptionlnlnitializerError
D. java.lang.ArraylndexOutOfBoundsException
Answer: C
Question 85
Given:
10. public class ClassA {
11. public void count(int i) {
12. count(++i);
13. }
14. }
And:
20. ClassA a = new ClassA();
21. a.count(3);
Which exception or error should be thrown by the virtual machine?
A. StackOverflowError
B. NullPointerException
C. NumberFormatException
D. IllegalArgumentException
E. ExceptionlnlnitializerError
Answer: A
Question 86
Given:
1. public class Boxer1 {
2. Integer i;
3. int x;
4. public Boxer1(int y) {
5. x=i+y;
6. System.out.println(x);
7. }
8. public static void main(String[] args) {
9. new Boxer1(new Integer(4));
10. }
11. }
What is the result?
A. The value “4” is printed at the command line.
B. Compilation fails because of an error in line 5.
C. Compilation fails because of an error in line 9.
D. A NullPointerException occurs at runtime.
E. A NumberFormatException occurs at runtime.
F. An IllegalStateException occurs at runtime.
Answer: D
Question 87
Given:
1. public class TestString 1 {
2. public static void main(String[] args) {
3. String str = “420”;
4. str += 42;
5. System.out.print(str);
6. }
7. }
What is the output?
A. 42
B. 420
C. 462
D. 42042
E. Compilation fails.
F. An exception is thrown at runtime.
Answer: D
Question 88
Given:
11. class Converter {
12. public static void main(String[] args) {
13. Integer i = args[0];
14. int j = 12;
15. System.out.println(”It is “ + (j==i) + “that j==i.”);
16. }
17. }
What is the result when the programmer attempts to compile the code
and run it with the command java Converter 12?
A. It is true that j==i.
B. It is false that j==i.
C. An exception is thrown at runtime.
D. Compilation fails because of an error in line 13.
Answer: D
Question 89
Given this method in a class:
21. public String toString() {
22. StringBuffer buffer = new StringBuffer();
23. buffer.append(’<’);
24. buffer.append(this.name);
25. buffer.append(’>’);
26. return buffer.toString();
27. }
Which is true?
A. This code is NOT thread-safe.
B. The programmer can replace StringBuffer with StringBuilder with no
other changes.
C. This code will perform well and converting the code to use
StringBuilder will not enhance the performance.
D. This code will perform poorly. For better performance, the code
should be rewritten: return “<“+ this.name + “>”;
Answer: B
Question 90
Given:
1. public class MyLogger {
2. private StringBuilder logger = new StringBuuilder();
3. public void log(String message, String user) {
4. logger.append(message);
5. logger.append(user);
6. }
7. }
The programmer must guarantee that a single MyLogger object works
properly for a multi-threaded system. How must this code be changed
to be thread-safe?
A. synchronize the log method
B. replace StringBuilder with StringBuffer
C. No change is necessary, the current MyLogger code is already
thread-safe.
D. replace StringBuilder with just a String object and use the string
concatenation (+=) within the log method
Answer: A
Question 91
Given:
11. public String makinStrings() {
12. String s = “Fred”;
13. s = s + “47”;
14. s = s.substring(2, 5);
15. s = s.toUpperCase();
16. return s.toString();
17. }
How many String objects will be created when this method is invoked?
A. 1
B. 2
C. 3
D. 4
E. 5
F. 6
Answer: C
Question 92
Given:
1. public class TestString3 {
2. public static void main(String[] args) {
3. // insert code here
5. System.out.println(s);
6. }
7. }
Which two code fragments, inserted independently at line 3, generate
the output 4247? (Choose two.)
A. String s = “123456789”;
s = (s-”123”).replace(1,3,”24”) - “89”;
B. StringBuffer s = new StringBuffer(”123456789”);
s.delete(0,3).replace( 1,3, “24”).delete(4,6);
C. StringBuffer s = new StringBuffer(”123456789”);
s.substring(3,6).delete( 1 ,3).insert( 1, “24”);
D. StringBuilder s = new StringBuilder(”123456789”);
s.substring(3,6).delete( 1 ,2).insert( 1, “24”);
E. StringBuilder s = new StringBuilder(”123456789”);
s.delete(0,3).delete( 1 ,3).delete(2,5).insert( 1, “24”);
Answer: BE
Question 93
Given:
11. public class Yikes {
12.
13. public static void go(Long n) {System.out.println(”Long “);}
14. public static void go(Short n) {System.out.println(”Short “);}
15. public static void go(int n) {System.out.println(”int “);}
16. public static void main(String [] args) {
17. short y= 6;
18. long z= 7;
19. go(y);
20. go(z);
21. }
22. }
What is the result?
A. int Long
B. Short Long
C. Compilation fails.
D. An exception is thrown at runtime.
Answer: A
Question 94
Given:
12. public class Wow {
13. public static void go(short n) {System.out.println(”short”); }
14. public static void go(Short n) {System.out.println(”SHORT”);}
15. public static void go(Long n) {System.out.println(” LONG”); }
16. public static void main(String [] args) {
17. Short y= 6;
18.int z=7;
19. go(y);
20. go(z);
21. }
22. }
What is the result?
A. short LONG
B. SHORT LONG
C. Compilation fails.
D. An exception is thrown at runtime.
Answer: C
Question 95
Given:
10. class MakeFile {
11. public static void main(String[] args) {
12. try {
13. File directory = new File(”d”);
14. File file = new File(directory,”f”);
15. if(!file.exists()) {
16. file.createNewFile();
17. }
18. } catch (IOException e) {
19. e.printStackTrace
20. }
21. }
22. }
The current directory does NOT contain a directory named “d.”
Which three are true? (Choose three.)
A. Line 16 is never executed.
B. An exception is thrown at runtime.
C. Line 13 creates a File object named “d.”
D. Line 14 creates a File object named “f.’
E. Line 13 creates a directory named “d” in the file system.
F. Line 16 creates a directory named “d” and a file ‘f’ within it in the
file system.
G. Line 14 creates a file named ‘f’ inside of the directory named “d” in
the file system.
Answer: BCD
Question 96
When comparing java.io.BufferedWriter to java.io.FileWriter, which
capability exists as a method in only one of the two?
A. closing the stream
B. flushing the stream
C. writing to the stream
D. marking a location in the stream
E. writing a line separator to the stream
Answer: E
Question 97
Given:
12. import java.io.*;
13. public class Forest implements Serializable {
14. private Tree tree = new Tree();
15. public static void main(String [] args) {
16. Forest f= new Forest();
17. try {
18. FileOutputStream fs = new FileOutputStream(”Forest.ser”);
19. ObjectOutputStream os = new ObjectOutputStream(fs);
20. os.writeObject(f); os.close();
21. } catch (Exception ex) { ex.printStackTrace(); }
22. } }
23.
24. class Tree { }
What is the result?
A. Compilation fails.
B. An exception is thrown at runtime.
C. An instance of Forest is serialized.
D. A instance of Forest and an instance of Tree are both serialized.
Answer: B
Question 98
Click the Exhibit button.
1. import java.io.*;
2. public class Foo implements Serializable {
3. public int x, y;
4. public Foo( int x, int y) { this.x = x; this.y = y; }
5.
6. private void writeObject( ObjectOutputStream s)
7. throws IOException {
8. s.writeInt(x); s.writeInt(y)
9. }
10.
11. private void readObject( ObjectInputStream s)
12. throws IOException, ClassNotFoundException {
13.
14. // insert code here
15.
16. }
17. }
Which code, inserted at line 14, will allow this class to correctly
serialize and deserialize?
A. s.defaultReadObject();
B. this = s.defaultReadObject();
C. y = s.readInt(); x = s.readInt();
D. x = s.readInt(); y = s.readInt();
Answer: D
Question 99
Which three concerning the use of the java.io.Serializable interface are
true? (Choose three.)
A. Objects from classes that use aggregation cannot be serialized.
B. Art object serialized on one JVM can be successfully deserialized on
a different JVM.
C. The values in fields with the volatile modifier will NOT survive
serialization and deserialization.
D. The values in fields with the transient modifier will NOT survive
serialization and deserialization.
E. It is legal to serialize an object of a type that has a supertype that
does NOT implement java.io.Serializable.
Answer: BDE
Question 100
Assuming that the serializeBanana() and the deserializeBanana()
methods will correctly use Java serialization and given:
13. import java.io.*;
14. class Food implemertts Serializable {int good = 3;}
15. class Fruit externds Food {int juice = 5;}
16. public class Banana extends Fruit {
17. int yellow = 4;
18. public static void main(String [] args) {
19. Banana b = new Banana(); Banana b2 = new Banana();
20. b.serializeBanana(b); // assume correct serialization
21. b2 = b.deserializeBanana(); // assume correct
22. System.out.println(”restore “+b2.yellow+ b2.juice+b2.good);
24. }
25. // more Banana methods go here
50. }
‘What is the result?
A. restore 400
B. restore 403
C. restore 453
D. Compilation fails.
E. An exception is thrown at runtime.
Answer: C
Question 101
Assuming that the serializeBanana2() and the deserializeBanana2()
methods will correctly use Java serialization and given:
13. import java.io.*;
14. class Food {Food() { System.out.print(”1”); } }
15. class Fruit extends Food implements Serializable {
16. Fruit() { System.out.print(”2”); } }
17. public class Banana2 extends Fruit { int size = 42;
18. public static void main(String [] args) {
19. Banana2 b = new Banana2();
20. b.serializeBanana2(b); // assume correct serialization
21. b = b.deserializeBanana2(b); // assume correct
22. System.out.println(” restored “+ b.size + “ “); }
23. // more Banana2 methods
24. }
What is the result?
A. Compilation fails.
B. 1 restored 42
C. 12 restored 42
D. 121 restored 42
E. 1212 restored 42
F. An exception is thrown at runtime.
Answer: D
Question 102
Given:
10. public class Foo implements java.io.Serializable {
11. private int x;
12. public int getX() { return x; }
12.publicFoo(int x){this.x=x; }
13. private void writeObject( ObjectOutputStream s)
14. throws IOException {
15. // insert code here
16. }
17. }
Which code fragment, inserted at line 15, will allow Foo objects to be
correctly serialized and deserialized?
A. s.writeInt(x);
B. s.serialize(x);
C. s.writeObject(x);
D. s.defaultWriteObject();
Answer: D
Question 103
Given:
12. NumberFormat nf= NumberFormat.getInstance();
13. nf.setMaximumFractionDigits(4);
14. nf.setMinimumFractionDigits(2);
15. String a = nf.format(3.1415926);
16. String b = nf.format(2);
Which two are true about the result if the default locale is Locale.US?
(Choose two.)
A. The value of b is 2.
B. The value of a is 3.14.
C. The value of b is 2.00.
D. The value of a is 3.141.
E. The value of a is 3.1415.
F. The value of a is 3.1416.
G. The value of b is 2.0000.
Answer: CF
Question 104
Given:
11. double input = 314159.26;
12. NumberFormat nf= NumberFormat.getInstance(Locale.ITALIAN);
13. String b;
14. //insert code here
Which code, inserted at line 14, sets the value of b to 3 14.159,26?
A. b = nf.parse( input);
B. b = nf.format( input);
C. b = nf.equals( input);
D. b = nf.parseObject( input);
Answer: B
Question 105
Given:
14. DateFormat df;
15. Date date = new Date();
16. //insert code here
17. String s = df.format( date);
Which two, inserted independently at line 16, allow the code to
compile? (Choose two.)
A. df= new DateFormat();
B. df= Date.getFormatter();
C. df= date.getFormatter();
D. df= date.getDateFormatter();
E. df= Date.getDateFormatter();
F. df= DateFormat.getInstance();
G. df = DateFormat.getDateInstance();
Answer: FG
Question 106
Given:
12. Date date = new Date();
13. df.setLocale(Locale.ITALY);
14. String s = df.format(date);
The variable df is an object of type DateFormat that has been
initialized in line 11. What is the result if this code is run on December
14, 2000?
A. The value of s is 14-dic-2004.
B. The value of s is Dec 14, 2000.
C. An exception is thrown at runtime.
D. Compilation fails because of an error in line 13.
Answer: D
Question 107
Given:
33. Date d = new Date(0);
34. String ds = “December 15, 2004”;
35. // insert code here
36. try {
37. d = df.parse(ds);
38. }
39. catch(ParseException e) {
40. System.out.println(”Unable to parse “+ ds);
41. }
42. // insert code here too
Which will create the appropriate DateFormat object and add a day to
the Date object?
A. 35. DateFormat df= DateFormat.getDateFormat();
42. d.setTime( (60 * 60 * 24) + d.getTime());
B. 35. DateFormat df= DateFormat.getDateJnstance();
42. d.setTime( (1000 * 60 * 60 * 24) + d.getTime());
C. 35. DateFormat df= DateFormat.getDateFormat();
42. d.setLocalTime( (1000*60*60*24) + d.getLocalTime());
D. 35. DateFormat df= DateFormat.getDateJnstance();
42. d.setLocalTime( (60 * 60 * 24) + d.getLocalTime());
Answer: B
Question 108
Given a valid DateFormat object named df, and
16. Date d = new Date(0L);
17. String ds = “December 15, 2004”;
18. // insert code here
What updates d’s value with the date represented by ds?
A. 18. d = df.parse(ds);
B. 18. d = df.getDate(ds);
C. 18. try {
19. d = df.parse(ds);
20. } catch(ParseException e) { };
D. 18. try {
19. d = df.getDate(ds);
20. } catch(ParseException e) { };
Answer: C
Question 109
Given:
11. String test = “This is a test”;
12. String[] tokens = test.split(”\s”);
13. System.out.println(tokens.length);
What is the result?
A. 0
B. 1
C. 4
D. Compilation fails.
E. An exception is thrown at runtime.
Answer: D
Question 110
Given:
11. String test= “a1b2c3”;
12. String[] tokens = test.split(”\\d”);
13. for(String s: tokens) System.out.print(s +“ “);
What is the result?
A. a b c
B. 1 2 3
C. a1b2c3
D. a1 b2 c3
E. Compilation fails.
F. The code runs with no output.
G. An exception is thrown at runtime.
Answer: A
Question 111
Given:
11. String test = “Test A. Test B. Test C.”;
12. // insert code here
13. String[] result = test.split(regex);
Which regular expression inserted at line 12 will correctly split test into
“Test A,” “Test B,” and “Test C”?
A. String regex = “”;
B. String regex = “ “;
C. String regex = “.*“.
D. String regex = “\\s”
E. String regex = “\\.\\s*”;
F. String regex = “\\w[ \.] +“;
Answer: E
Question 112
Given:
12. System.out.format(”Pi is approximately %d.”, Math.PI);
What is the result?
A. Compilation fails.
B. Pi is approximately 3.
C. Pi is approximately 3.141593.
D. An exception is thrown at runtime.
Answer: D
Question 113
Given:
12. String csv = “Sue,5,true,3”;
13. Scanner scanner = new Scanner( csv);
14. scanner.useDelimiter(”,”);
15. int age = scanner.nextInt();
What is the result?
A. Compilation fails.
B. After line 15, the value of age is 5.
C. After line 15, the value of age is 3.
D. An exception is thrown at runtime.
Answer: D
Question 114
Which two code fragments will execute the method doStuff() in a
separate thread? (Choose two.)
A. new Thread() {
public void run() { doStuff(); }
}
B. new Thread() {
public void start() { doStuff(); }
}
C. new Thread() {
public void start() { doStuff(); }
} .run();
D. new Thread() {
public void run() { doStuff(); }
} .start();
E. new Thread(new Runnable() {
public void run() { doStuff(); }
} ).run();
F. new Thread(new Runnable() {
public void run() { doStuff(); }
}).start();
Answer: DF
Question 115
Given:
1. public class Threads3 implements Runnable {
2. public void run() {
3. System.out.print(”running”);
4. }
5. public static void main(String[] args) {
6. Thread t = new Thread(new Threads3());
7. t.run();
8. t.run();
9. t.start();
10. }
11. }
What is the result?
A. Compilation fails.
B. An exception is thrown at runtime.
C. The code executes and prints “running”.
D. The code executes and prints “runningrunning”.
E. The code executes and prints “runningrunningrunning”.
Answer: E
Question 116
Given:
1. public class Threads4 {
2. public static void main (String[] args) {
3. new Threads4().go();
4. }
5. public void go() {
6. Runnable r = new Runnable() {
7. public void run() {
8. System.out.print(”foo”);
9. }
10. };
11. Thread t = new Thread(r);
12. t.start();
13. t.start();
14. }
15. }
What is the result?
A. Compilation fails.
B. An exception is thrown at runtime.
C. The code executes normally and prints ‘foo”.
D. The code executes normally, but nothing is printed.
Answer: B
Question 117
Given:
1. public class Threads5 {
2. public static void main (String[] args) {
3. new Thread(new Runnable() {
4. public void run() {
5. System.out.print(”bar”);
6. }}).start();
7. }
8. }
What is the result?
A. Compilation fails.
B. An exception is thrown at runtime.
C. The code executes normally and prints “bar”.
D. The code executes normally, but nothing prints.
Answer: C
Question 118
Given:
11. Runnable r = new Runnable() {
12. public void run() {
13. System.out.print(”Cat”);
14. }
15. };
16. Threadt=new Thread(r) {
17. public void run() {
18. System.out.print(”Dog”);
19. }
20. };
21. t.start();
What is the result?
A. Cat
B. Dog
C. Compilation fails.
D. The code runs with no output.
E. An exception is thrown at runtime.
Answer: B
Question 119
Click the Exhibit button.
Given:
10. public class Starter extends Thread {
11. private int x= 2;
12. public static void main(String[] args) throws Exception {
13. new Starter().makeItSo();
14. }
15. public Starter() {
16. x=5;
17. start();
18. }
19. public void makeItSo() throws Exception {
20. join();
21. x=x- 1;
22. System.out.println(x);
23. }
24. public void run() { x *= 2; }
25. }
What is the output if the main() method is rum?
A. 4
B. 5
C. 8
D. 9
E. Compilation fails.
F. An exception is thrown at runtime.
G. It is impossible to determine for certain.
Answer: D
Question 120
Given:
1. public class Threads2 implements Runnable {
2.
3. public void nun() {
4. System.out.println(”run.”);
5. throw new RuntimeException(”Problem”);
6. }
7. public static void main(String[] args) {
8. Thread t = new Thread(new Threads2());
9. t.start();
10. System.out.println(”End of method.”);
11. }
12. }
Which two can be results? (Choose two.)
A. java.lang.RuntimeException: Problem
B. run.
java.lang.RuntimeException: Problem
C. End of method.
java.lang.RuntimeException: Problem
D. End of method.
run.
java.lang.RuntimeException: Problem
E. run.
java.lang.RuntimeException: Problem
End of method.
Answer: DE
Question 121
Given:
1. public class TestOne {
2. public static void main (String[] args) throws Exception {
3. Thread.sleep(3000);
4. System.out.println(”sleep”);
5. }
6. }
What is the result?
A. Compilation fails.
B. An exception is thrown at runtime.
C. The code executes normally and prints “sleep”.
D. The code executes normally, but nothing is printed.
Answer: C
Question 122
Given:
1. public class TestOne implements Runnable {
2. public static void main (String[] args) throws Exception {
3. Thread t = new Thread(new TestOne());
4. t.start();
5. System.out.print(”Started”);
6. t.join();
7. System.out.print(”Complete”);
8. }
9. public void run() {
10. for (int i= 0; i< 4; i++) {
11. System.out.print(i);
12. }
13. }
14. }
What can be a result?
A. Compilation fails.
B. An exception is thrown at runtime.
C. The code executes and prints “StartedComplete”.
D. The code executes and prints “StartedComplete0123”.
E. The code executes and prints “Started0l23Complete”.
Answer: E
Question 123
Click the Exhibit button.
Given:
1. public class TwoThreads {
2
3. private static Object resource = new Object();
4.
5. private static void delay(long n) {
6. try { Thread.sleep(n); }
7. catch (Exception e) { System.out.print(”Error “); }
8. }
9
10. public static void main(String[] args) {
11. System.out.print(”StartMain “);
12. new Thread1().start();
13. delay(1000);
14. Thread t2 = new Thread2();
15. t2.start();
16. delay(1000);
17. t2.interrupt
18. delay(1000);
19. System.out.print(”EndMain “);
20. }
21.
22. static class Thread 1 extends Thread {
23. public void run() {
24. synchronized (resource) {
25. System.out.print(”Startl “);
26. delay(6000);
27. System.out.print(”End1 “);
28. }
29. }
30. }
31.
32. static class Thread2 extends Thread {
33. public void run() {
34. synchronized (resource) {
35. System.out.print(”Start2 “);
36. delay(2000);
37. System.out.print(”End2 “);
38. }
39. }
40. }
41. }
Assume that sleep(n) executes in exactly m milliseconds, and all other
code executes in an insignificant amount of time. What is the output if
the main() method is run?
A. Compilation fails.
B. Deadlock occurs.
C. StartMain Start1 Error EndMain End1
D. StartMain Start1 EndMain End1 Start2 End2
E. StartMain Start1 Error Start2 EndMain End2 End1
F. StartMain Start1 Start2 Error End2 EndMain End1
G. StartMain Start1 EndMain End1 Start2 Error End2
Answer: G
Question 125
Given:
public class NamedCounter {
private final String name;
private int count;
public NamedCounter(String name) { this.name = name; }
public String getName() { return name; }
public void increment() { coount++; }
public int getCount() { return count; }
public void reset() { count = 0; }
}
Which three changes should be made to adapt this class to be used
safely by multiple threads? (Choose three.)
A. declare reset() using the synchronized keyword
B. declare getName() using the synchronized keyword
C. declare getCount() using the synchronized keyword
D. declare the constructor using the synchronized keyword
E. declare increment() using the synchronized keyword
Answer: ACE
Question 125
Click the Exhibit button:
1. public class Threads 1 {
2. intx=0;
3. public class Runner implements Runnable {
4. public void run() {
5. int current = 0;
6. for(int=i=0;i<4;i++){
7. current = x;
8. System.out.print(current + “, “);
9. x = current + 2;
10. }
11. }
12. }
13.
14. public static void main(String[] args) {
15. new Threads1().go();
16. }
17.
18. public void go() {
19. Runnable r1 = new Runner();
20. new Thread(r1).start();
21. new Thread(r1 ).start();
22. }
23. }
Which two are possible results? (Choose two.)
A. 0, 2, 4, 4, 6, 8, 10, 6,
B. 0, 2, 4, 6, 8, 10, 2, 4,
C. 0, 2, 4, 6, 8, 10, 12, 14,
D. 0, 0, 2, 2, 4, 4, 6, 6, 8, 8, 10, 10, 12, 12, 14, 14,
E. 0, 2, 4, 6, 8, 10, 12, 14, 0, 2, 4, 6, 8, 10, 12, 14,
Answer: AC
Question 126
Click the Exhibit button.
1. import java.util.*;
2.
3. public class NameList {
4. private List names = new ArrayList();
5. public synchronized void add(String name) { names.add(name); }
6. public synchronized void printAll() {
7. for (int i = 0; i <names.size(); i++) {
8. System.out.print(names.get(i) +“ “);
9. }
10. }
11. public static void main(String[] args) {
12. final NameList sl = new NameList();
13.for(int i=0;i<2;i++) {
14. new Thread() {
15. public void ruin() {
16. sl.add(”A”);
17. sl.add(”B”);
18. sl.add(”C”);
19. sl.printAll();
20. }
21. }.start();
22. }
23. }
24. }
Which two statements are true if this class is compiled and run?
(Choose two.)
A. An exception may be thrown at runtime.
B. The code may run with no output, without exiting.
C. The code may run with no output, exiting normally.
D. The code may rum with output “A B A B C C “, then exit.
E. The code may rum with output “A B C A B C A B C “, then exit.
F. The code may ruin with output “A A A B C A B C C “, then exit.
G. The code may ruin with output “A B C A A B C A B C “, then exit.
Answer: EG
Question 127
Given:
1. public class TestFive {
2. private int x;
3. public void foo() {
4 int current = x;
5. x = current + 1;
6. }
7. public void go() {
8. for(int i=0;i<5;i++) {
9. new Thread() {
10. public void run() {
11. foo();
12. System.out.print(x + “, “);
13. } }.start();
14. }}}
Which two changes, taken together, would guarantee the output: 1, 2,
3, 4, 5, ? (Choose two.)
A. Move the line 12 print statement into the foo() method.
B. Change line 7 to public synchronized void go() {.
C. Change the variable declaration on line 3 to private volatile int x;.
D. Wrap the code inside the foo() method with a synchronized( this )
block.
E. Wrap the for loop code inside the go() method with a synchronized
block synchronized(this) { // for loop code here }.
Answer: AD
Question 128
Which three will compile and rim without exception? (Choose three.)
A. private synchronized Object o;
B. void go() {
synchronized() { /* code here */ }
}
C. public synchronized void go() { /* code here */ }
D. private synchronized(this) void go() { /* code here */ }
E. void go() {
synchronized(Object.class) { /* code here */ }
}
F. void go() {
Object o = new Object();
synchronized(o) { /* code here */ }
}
Answer: CEF
Question 129
Given:
1. public class TestSeven extends Thread {
2. private static int x;
3. public synchronized void doThings() {
4. int current = x;
5. current++;
6. x = current;
7. }
8. public void run() {
9. doThings();
10. }
1 1.}
Which is true?
A. Compilation fails.
B. An exception is thrown at runtime.
C. Synchronizing the run() method would make the class thread-safe.
D. The data in variable “x” are protected from concurrent access
problems.
E. Declaring the doThings() method as static would make the class
thread-safe.
F. Wrapping the statements within doThings() in a synchronized(new
Object()) { } block would make the class thread-safe.
Answer: E
Question 130
Click the Exhibit button.
10. public class Transfers {
11. public static void main(String[] args) throws Exception {
12. Record r1 = new Record();
13. Record r2 = new Record();
14. doTransfer(r1, r2, 5);
15. doTransfer(r2, r1, 2);
16. doTransfer(r1, r2, 1);
17. // print the result
18. System.out.println(”rl = “ + r1.get() +“, r2=” + r2.get());
19. }
20. private static void doTransfer(
21. final Record a, final Record b, final int amount) {
22. Thread t = new Thread() {
23. public void run() {
24. new Clerk().transfer(a, b, amount);
25. }
26. };
27. t.start();
28. }
29. }
30. class Clerk {
31. public synchronized void transfer(Record a, Record b, int amount){
32. synchronized (a) {
33. synchronized (b) {
34. a.add(-amount);
35. b.add(amount);
36. }
37. }
38. }
39. }
40. class Record {
41.int num=10;
42. public int get() { return num; }
43. public void add(int n) { num = num + n; }
44. }
If Transfers.main() is run, which three are true? (Choose three.)
A. The output may be “r1 = 6, r2 = 14”.
B. The output may be “r1 = 5, r2 = 15”.
C. The output may be “r1 = 8, r2 = 12”.
D. The code may run (and complete) with no output.
E. The code may deadlock (without completing) with no output.
F. M IllegalStateException or InterruptedException may be thrown at
runtime.
Answer: ABE
Question 131
Click the Exhibit button.
1. class Computation extends Thread {
2.
3. private int num;
4. private boolean isComplete;
5. private int result;
6.
7. public Computation(int num) { this.num = num; }
8.
9. public synchronized void run() {
10. result = num * 2;
11. isComplete = true;
12. notify();
13. }
14.
15. public synchronized int getResult() {
16. while (!isComplete) {
17. try {
18. wait();
19. } catch (InterruptedException e) { }
20. }
21. return result;
22. }
23.
24. public static void main(String[] args) {
25. Computation[] computations = new Computation [4];
26. for (int i = 0; i < computations.length; i++) {
27. computations[i] = new Computation(i);
28. computations[i] .start();
29. }
30. for (Computation c : computations)
31. System.out.print(c.getResult() +“ “);
32. }
33. }
What is the result?
A. The code will deadlock.
B. The code may run with no output.
C. An exception is thrown at runtime.
D. The code may run with output “0 6”.
E. The code may run with output “2 0 6 4’.
F. The code may ruin with output “0 2 4 6”.
Answer: F
Question 132
Given:
7. void waitForSignal() {
8. Object obj = new Object();
9. synchronized (Thread.currentThread()) {
10. obj.wait();
11. obj.notify();;
12. }
13. }
Which is true?
A. This code may throw an InterruptedException.
B. This code may throw an IllegalStateException.
C. This code may throw a TimeoutException after ten minutes.
D. This code will not compile unless “obj.wait()” is replaced with
“((Thread) obj).wait()”.
E. Reversing the order of obj.wait() and obj.notify() may cause this
method to complete normally.
F. A call to notify() or notifyAll() from another thread may cause this
method to complete normally.
Answer: B
Question 133
Given:
foo and bar are public references available to many other threads. foo
refers to a Thread and bar is an Object. The thread foo is currently
executing bar.wait(). From another thread, which statement is the
most reliable way to ensue that foo will stop executing wait()?
A. foo.notify();
B. bar.notify();
C. foo.notifyAll();
D. Thread.notify();
E. bar.notiFYAll();
F. Object.notify();
Answer: E
Question 134
Which two are true? (Choose two.)
A. An encapsulated, public class promotes re-use.
B. Classes that share the same interface are always tightly
encapsulated.
C. An encapsulated class allows subclasses to overload methods, but
does NOT allow overriding methods.
D. An encapsulated class allows a programmer to change an
implementation without affecting outside code.
Answer: AD
Question 135
Given:
1. package test;
2.
3. class Target {
4. public String name = “hello”;
5. }
What can directly access and change the value of the variable name?
A. any class
B. only the Target class
C. any class in the test package
D. any class that extends Target
Answer: C
Question 136
Given:
1. public class Target {
2. private int i = 0;
3. public int addOne() {
4. return ++i;
5. }
6. }
And:
1. public class Client {
2. public static void main(String[] args) {
3. System.out.println(new Target().addOne());
4. }
5. }
Which change can you make to Target without affecting Client?
A. Line 4 of class Target can be changed to return i++;
B. Line 2 of class Target can be changed to private int i = 1;
C. Line 3 of class Target can be changed to private int addOne() {
D. Line 2 of class Target can be changed to private Integer i = 0;
Answer: D
Question 137
Given:
1. package geometry;
2. public class Hypotenuse {
3. public InnerTriangle it = new InnerTriangle();
4. class InnerTriangle {
5. public int base;
6. public int height;
7. }
8. }
Which is true about the class of an object that can reference the
variable base?
A. It can be any class.
B. No class has access to base.
C. The class must belong to the geometry package.
D. The class must be a subclass of the class Hypotenuse.
Answer: C
Question 138
Given:
11. class ClassA {}
12. class ClassB extends ClassA {}
13. class ClassC extends ClassA {}
and:
21. ClassA p0 = new ClassA();
22. ClassB p1 = new ClassB();
23. ClassC p2 = new ClassC();
24. ClassA p3 = new ClassB();
25. ClassA p4 = new ClassC();
Which three are valid? (Choose three.)
A. p0 = p1;
B. p1 =p2;
C. p2 = p4;
D. p2 = (ClassC)p1;
E. p1 = (ClassB)p3;
F. p2 = (ClassC)p4;
Answer: AEF
Question 139
Given:
11. class Animal { public String noise() { return “peep”; } }
12. class Dog extends Animal {
13. public String noise() { return “bark”; }
14. }
15. class Cat extends Animal {
16. public String noise() { return “meow”; }
17. }
.....
30. Animal animal = new Dog();
31. Cat cat = (Cat)animal;
32. System.out.printIn(cat.noise());
What is the result?
A. peep
B. bark
C. meow
D. Compilation fails.
E. An exception is thrown at runtime.
Answer: E
Question 140
Given:
11. abstract class Vehicle { public int speed() { return 0; } }
12. class Car extends Vehicle { public int speed() { return 60; } }
13. class RaceCar extends Car { public int speed() { return 150; }}
......
21. RaceCar racer = new RaceCar();
22. Car car = new RaceCar();
23. Vehicle vehicle = new RaceCar();
24. System.out.println(racer.speed() + “, ‘ + car.speed()
25. + “, “+ vehicle.speed());
What is the result?
A. 0, 0,0
B. 150, 60, 0
C. Compilation fails.
D. 150, 150, 150
E. An exception is thrown at runtime.
Answer: D
Question 141
Given:
10. abstract class A {
11. abstract void al();
12. void a2() { }
13. }
14. class B extends A {
15. void a1() { }
16. void a2() { }
17. }
18. class C extends B { void c1() { } }
and:
A x = new B(); C y = new C(); A z = new C();
Which four are valid examples of polymorphic method calls? (Choose
four.)
A. x.a2();
B. z.a2();
C. z.c1();
D. z.a1();
E. y.c1();
F. x.a1();
Answer: ABDF
Question 142
Given:
10. interface A { void x(); }
11. class B implements A { public void x() { } public voidy() { } }
12. class C extends B { public void x() {} }
And:
20. java.util.List<A> list = new java.util.ArrayList<A>();
21. list.add(new B());
22. list.add(new C());
23. for (A a:list) {
24. a.x();
25. a.y();;
26. }
What is the result?
A. The code runs with no output.
B. An exception is thrown at runtime.
C. Compilation fails because of an error in line 20.
D. Compilation fails because of an error in line 21.
E. Compilation fails because of an error in line 23.
F. Compilation fails because of an error in line 25.
Answer: F
Question 143
Given:
1. class SuperClass {
2. public A getA() {
3. return new A();
4. }
5. }
6. class SubClass extends SuperClass {
7. public B getA() {
8. return new B();
9. }
10. }
Which is true?
A. Compilation will succeed if A extends B.
B. Compilation will succeed if B extends A.
C. Compilation will always fail because of an error in line 7.
D. Compilation will always fail because of an error in line 8.
Answer: B
Question 144
Given:
1. interface A { public void aMethod(); }
2. interface B { public void bMethod(); }
3. interface C extends A,B { public void cMethod(); }
4. class D implements B {
5. public void bMethod() { }
6. }
7. class E extends D implements C {
8. public void aMethod() { }
9. public void bMethod() { }
10. public void cMethod() { }
11. }
What is the result?
A. Compilation fails because of an error in line 3.
B. Compilation fails because of an error in line 7.
C. Compilation fails because of an error in line 9.
D. If you define D e = new E(), then e.bMethod() invokes the version
of bMethod() defined in Line 5.
E. If you define D e = (D)(new E()), then e.bMethod() invokes the
version of bMethod() defined in Line 5.
F. If you define D e = (D)(new E()), then e.bMethod() invokes the
version of bMethod() defined in Line 9.
Answer: F
Question 145
Given:
10. interface A { public int getValue() }
11. class B implements A {
12. public int getValue() { return 1; }
13. }
14. class C extends B {
15. // insert code here
16. }
Which three code fragments, inserted individually at line 15, make use
of polymorphism? (Choose three.)
A. public void add(C c) { c.getValue(); }
B. public void add(B b) { b.getValue(); }
C. public void add(A a) { a.getValue(); }
D. public void add(A a, B b) { a.getValue(); }
E. public void add(C c1, C c2) { c1.getValue(); }
Answer: BCD
Question 146
Given:
1. class ClassA {
2. public int numberOfinstances;
3. protected ClassA(int numberOfinstances) {
4. this.numberOflnstances = numberOfinstances;
5. }
6. }
7. public class ExtendedA extends ClassA {
8. private ExtendedA(int numberOfinstances) {
9. super(numberOflnstances);
10. }
11. public static void main(String[] args) {
12. ExtendedA ext = new ExtendedA(420);
13. System.out.print(ext.numberOflnstances);
14. }
15. }
Which is true?
A. 420 is the output.
B. An exception is thrown at runtime.
C. All constructors must be declared public.
D. Constructors CANNOT use the private modifier.
E. Constructors CANNOT use the protected modifier.
Answer: A
Question 147
147. Given:
1. public class Base {
2. public static final String FOO = “foo”;
3. public static void main(String[] args) {
4. Base b = new Base();
5. Sub s = new Sub();
6. System.out.print(Base.FOO);
7. System.out.print(Sub.FOO);
8. System.out.print(b.FOO);
9. System.out.print(s.FOO);
10. System.out.print(((Base)s).FOO);
11. } }
12. class Sub extends Base {public static final String FOO=bar;}
What is the result?
A. foofoofoofoofoo
B. foobarfoobarbar
C. foobarfoofoofoo
D. foobarfoobarfoo
E. barbarbarbarbar
F. foofoofoobarbar
G. foofoofoobarfoo
Answer: D
Question 148
Which three statements are true? (Choose three.)
A. A final method in class X can be abstract if and only if X is abstract.
B. A protected method in class X can be overridden by any subclass of
X.
C. A private static method can be called only within other static
methods in class X.
D. A non-static public final method in class X can be overridden in any
subclass of X.
E. A public static method in class X can be called by a subclass of X
without explicitly referencing the class X.
F. A method with the same signature as a private final method in class
X can be implemented in a subclass of X.
G. A protected method in class X can be overridden by a subclass of A
only if the subclass is in the same package as X.
Answer: BEF
Question 149
Given:
1. class Pizza {
2. java.util.ArrayList toppings;
3. public final void addTopping(String topping) {
4. toppings.add(topping);
5. }
6. }
7. public class PepperoniPizza extends Pizza {
8. public void addTopping(String topping) {
9. System.out.println(”Cannot add Toppings”);
10. }
11. public static void main(String[] args) {
12. Pizza pizza = new PepperoniPizza();
13. pizza.addTopping(”Mushrooms”);
14. }
15. }
What is the result?
A. Compilation fails.
B. Cannot add Toppings
C. The code runs with no output.
D. A NullPointerException is thrown in Line 4.
Answer: A
Question 150
Given:
1. class Super {
2. private int a;
3. protected Super(int a) { this.a = a; }
4. }
.....
11. class Sub extends Super {
12. public Sub(int a) { super(a); }
13. public Sub() { this.a= 5; }
14. }
Which two, independently, will allow Sub to compile? (Choose two.)
A. Change line 2 to:
public int a;
B. Change line 2 to:
protected int a;
C. Change line 13 to:
public Sub() { this(5); }
D. Change line 13 to:
public Sub() { super(5); }
E. Change line 13 to:
public Sub() { super(a); }
Answer: CD
Question 151
Click the Exhibit button.
1. public class SimpleCalc {
2. public int value;
3. public void calculate() { value += 7; }
4. }
And:
1. public class MultiCalc extends SimpleCalc {
2. public void calculate() { value -= 3; }
3. public void calculate(int multiplier) {
4. calculate();
5. super.calculate();
6. value *=multiplier;
7. }
8. public static void main(String[] args) {
9. MultiCalc calculator = new MultiCalc();
10. calculator.calculate(2);
11. System.out.println(”Value is: “+ calculator.value);
12. }
13. }
What is the result?
A. Value is: 8
B. Compilation fails.
C. Value is: 12
D. Value is: -12
E. The code runs with no output.
F. An exception is thrown at runtime.
Answer: A
Question 152
Given:
10. public class Hello {
11. String title;
12. int value;
13. public Hello() {
14. title += “ World”;
15. }
16. public Hello(int value) {
17. this.value = value;
18. title = “Hello”;
19. Hello();
20. }
21. }
and:
30. Hello c = new Hello(5);
31. System.out.println(c.title);
What is the result?
A. Hello
B. Hello World
C. Compilation fails.
D. Hello World 5
E. The code runs with no output.
F. An exception is thrown at runtime.
Answer: C
Question 153
Click the Exhibit button.
1. public class Car {
2. private int wheelCount;
3. private String vin;
4. public Car(String vin) {
5. this.vin = vin;
6. this.wheelCount = 4;
7. }
8. public String drive() {
9. return “zoom-zoom”;
10. }
11. public String getInfo() {
12. return “VIN: “+ vin + “wheels: “+ wheelCount;
13. }
14. }
And:
1. public class MeGo extends Car {
2. public MeGo(String vin) {
3. this.wheelCount = 3;
4. }
5. }
What two must the programmer do to correct the compilation errors?
(Choose two.)
A. insert a call to this() in the Car constructor
B. insert a call to this() in the MeGo constructor
C. insert a call to super() in the MeGo constructor
D. insert a call to super(vin) in the MeGo constructor
E. change the wheelCount variable in Car to protected
F. change line 3 in the MeGo class to super.wheelCount = 3;
Answer: DE
Question 154
Click the Exhibit button.
1. public class Employee {
2. String name;
3. double baseSalary;
4. Employee(String name, double baseSalary) {
5. this.name = name;
6. this.baseSalary = baseSalary;
7. }
8. }
And:
1. public class Salesperson extends Employee {
2. double commission;
3. public Salesperson(String name, double baseSalary,
4. double commission) {
5. // insert code here
6. }
7. }
Which code, inserted at line 7, completes the Salesperson constructor?
A. this.commission = commission;
B. superb();
commission = commission;
C. this.commission = commission;
superb();
D. super(name, baseSalary);
this.commission = commission;
E. super();
this.commission = commission;
F. this.commission = commission;
super(name, baseSalary);
Answer: D
Question 155
Given:
1. public class Blip {
2. protected int blipvert(int x) { return 0; }
3. }
4. class Vert extends Blip {
5. // insert code here
6. }
Which five methods, inserted independently at line 5, will compile?
(Choose five.)
A. public int blipvert(int x) { return 0; }
B. private int blipvert(int x) { return 0; }
C. private int blipvert(long x) { return 0; }
D. protected long blipvert(int x) { return 0; }
E. protected int blipvert(long x) { return 0; }
F. protected long blipvert(long x) { return 0; }
G. protected long blipvert(int x, int y) { return 0; }
Answer: ACEFG
Question156
Given:
10. public class Foo {
11. public int a;
12. public Foo() { a = 3; }
13. public void addFive() { a += 5; }
14. }
and:
20. public class Bar extends Foo {
21. public int a;
22. public Bar() { a = 8; }
23. public void addFive() { this.a +=5; }
24. }
invoked with:
30. Foo foo = new Bar();
31. foo.addFive();
32. System.out.println(”Value: “+ foo.a);
What is the result?
A. Value: 3
B. Value: 8
C. Value: 13
D. Compilation fails.
E. The code runs with no output.
F. An exception is thrown at runtime.
Answer: A
Question 157
Given:
10. public class SuperCaic {
11. protected static int multiply(int a, int b) { return a * b; }
12. }
and:
20. public class SubCalc extends SuperCalc {
21. public static int multiply(int a, int b) {
22. int c = super.multiply(a, b);
23. return c;
24. }
25. }
and:
30. SubCalc sc = new SubCalc();
31. System.out.println(sc.multiply(3,4));
32. System.out.println(SubCalc.multiply(2,2));
What is the result?
A. 12
4
B. The code runs with no output.
C. An exception is thrown at runtime.
D. Compilation fails because of an error in line 21.
E. Compilation fails because of an error in line 22.
F. Compilation fails because of an error in line 31.
Answer: E
Question 158
Given:
1. public class Team extends java.util.LinkedList {
2. public void addPlayer(Player p) {
3. add(p);
4. }
5. public void compete(Team opponent) { /* more code here */ }
6. }
7. class Player { /* more code here */ }
Which two are true? (Choose two.)
A. This code will compile.
B. This code demonstrates proper design of an is-a relationship.
C. This code demonstrates proper design of a has-a relationship.
D. A Java programmer using the Team class could remove Player
objects from a Team object.
Answer: AD
Question 159
Which four are true? (Choose four.)
A. Has-a relationships should never be encapsulated.
B. Has-a relationships should be implemented using inheritance.
C. Has-a relationships can be implemented using instance variables.
D. Is-a relationships can be implemented using the extends keyword.
E. Is-a relationships can be implemented using the implements
keyword.
F. The relationship between Movie and Actress is an example of an is-a
relationship.
G. An array or a collection can be used to implement a one-to-many
has-a relationship.
Answer: CDEG
Question 160
Which two are true about has-a and is-a relationships? (Choose two.)
A. Inheritance represents an is-a relationship.
B. Inheritance represents a has-a relationship.
C. Interfaces must be used when creating a has-a relationship.
D. Instance variables can be used when creating a has-a relationship.
Answer: AD
Question 161
Given:
10. interface Jumper { public void jump(); }
......
20. class Animal {}
......
30. class Dog extends Animal {
31. Tail tail;
32. }
......
40. class Beagle extends Dog implements Jumper {
41. public void jump() { }
42. }
.......
50. class Cat implements Jumper {
51. public void jump() { }
52. }
Which three are true? (Choose three.)
A. Cat is-a Animal
B. Cat is-a Jumper
C. Dog is-a Animal
D. Dog is-a Jumper
E. Cat has-a Animal
F. Beagle has-a Tail
G. Beagle has-a Jumper
Answer: BCF
Question 162
Given:
1. import java.util.*;
2. public class Example {
3. public static void main(String[] args) {
4. // insert code here
5. set.add(new integer(2));
6. set.add(new integer(l));
7. System.out.println(set);
8. }
9. }
Which code, inserted at line 4, guarantees that this program will
output [1, 2]?
A. Set set = new TreeSet();
B. Set set = new HashSet();
C. Set set = new SortedSet();
D. List set = new SortedList();
E. Set set = new LinkedHashSet();
Answer: A
Question 163
Given:
1. import java.util.*;
2. public class PQ {
3. public static void main(String[] args) {
4. PriorityQueue<String> pq = new PriorityQueue<String>();
5. pq.add(”carrot”);
6. pq.add(”apple”);
7. pq.add(”banana”);
8. System.out.println(pq.poll() +”:” + pq.peek());
9. }
10. }
What is the result?
A. apple:apple
B. carrot:apple
C. apple:banana
D. banana:apple
E. carrot:carrot
F. carrot:banana
Answer: C
Question 164
Given:
1. import java.util.*;
2. public class WrappedString {
3. private String s;
4. public WrappedString(String s) { this.s = s; }
5. public static void main(String[] args) {
6. HashSet<Object> hs = new HashSet<Object>();
7. WrappedString ws1 = new WrappedString(”aardvark”);
8. WrappedString ws2 = new WrappedString(”aardvark”);
9. String s1 = new String(”aardvark”);
10. String s2 = new String(”aardvark”);
11. hs.add(ws1); hs.add(ws2); hs.add(s1); hs.add(s2);
12. System.out.println(hs.size()); } }
What is the result?
A. 0
B. 1
C. 2
D. 3
E. 4
F. Compilation fails.
G. An exception is thrown at runtime.
Answer: D
Question 165
Click the Exhibit button.
1. import java.util.*;
2. public class TestSet {
3. enum Example { ONE, TWO, THREE }
4. public static void main(String[] args) {
5. Collection coll = new ArrayList();
6. coll.add(Example.THREE);
7. coll.add(Example.THREE);
8. coll.add(Example.THREE);
9. coll.add(Example.TWO);
10. coll.add(Example.TWO);
11. coll.add(Example.ONE);
12. Set set = new HashSet(coll);
13. }
14. }
Which statement is true about the set variable on line 12?
A. The set variable contains all six elements from the coll collection,
and the order is guaranteed to be preserved.
B. The set variable contains only three elements from the coll
collection, and the order is guaranteed to be preserved.
C. The set variable contains all six elements from the coil collection,
but the order is NOT guaranteed to be preserved.
D. The set variable contains only three elements from the coil
collection, but the order is NOT guaranteed to be preserved.
Answer: D
Question 166
Given:
1. public class Score implements Comparable<Score> {
2. private int wins, losses;
3. public Score(int w, int 1) { wins = w; losses = 1; }
4. public int getWins() { return wins; }
5. public int getLosses() { return losses; }
6. public String toString() {
7. return “<“ + wins + “,“ + losses + “>”;
8. }
9. // insert code here
10. }
Which method will complete this class?
A. public int compareTo(Object o) {/*mode code here*/}
B. public int compareTo(Score other) {/*more code here*/}
C. public int compare(Score s1,Score s2){/*more code here*/}
D. public int compare(Object o1,Object o2){/*more code here*/}
Answer: B
Question 167
A programmer has an algorithm that requires a java.util.List that
provides an efficient implementation of add(0,object), but does
NOT need to support quick random access. What supports these
requirements?
A. java.util.Queue
B. java.util.ArrayList
C. java.util.LinearList
D. java.util.LinkedList
Answer: D
Question 168
Given:
11. public class Person {
12. private String name, comment;
13. private int age;
14. public Person(String n, int a, String c) {
15. name = n; age = a; comment = c;
16. }
17. public boolean equals(Object o) {
18. if(! (o instanceof Person)) return false;
19, Person p = (Person)o;
20. return age == p.age && name.equals(p.name);
21. }
22. }
What is the appropriate definition of the hashCode method in class
Person?
A. return super.hashCode();
B. return name.hashCode() + age * 7;
C. return name.hashCode() + comment.hashCode() /2;
D. return name.hashCode() + comment.hashCode() / 2 - age * 3;
Answer: B
Question 169
Given:
11. public class Key {
12. private long id1;
13. private long 1d2;
14.
15. // class Key methods
16. }
A programmer is developing a class Key, that will be used as a key in
a standard java.util.HashMap. Which two methods should be
overridden to assure that Key works correctly as a key? (Choose two.)
A. public int hashCode()
B. public boolean equals(Key k)
C. public int compareTo(Object o)
D. public boolean equals(Object o)
E. public boolean compareTo(Key k)
Answer: AD
Question 170
Given:
11. public class Person {
12. private name;
13. public Person(String name) {
14. this.name = name;
15. }
16. public boolean equals(Object o) {
17. if( !o instanceof Person ) return false;
18. Person p = (Person) o;
19. return p.name.equals(this.name);
20. }
21. }
Which is true?
A. Compilation fails because the hashCode method is not overridden.
B. A HashSet could contain multiple Person objects with the same
name.
C. All Person objects will have the same hash code because the
hashCode method is not overridden.
D. If a HashSet contains more than one Person object with
name=”Fred”, then removing another Person, also with name=”Fred”,
will remove them all.
Answer: B
Question 171
Given:
1. public class Person {
2. private String name;
3. public Person(String name) { this.name = name; }
4. public boolean equals(Person p) {
5. return p.name.equals(this.name);
6. }
7. }
Which is true?
A. The equals method does NOT properly override the Object.equals
method.
B. Compilation fails because the private attribute p.name cannot be
accessed in line 5.
C. To work correctly with hash-based data structures, this class must
also implement the hashCode method.
D. When adding Person objects to a java.util.Set collection, the equals
method in line 4 will prevent duplicates.
Answer: A
Question 172
Which two statements are true about the hashCode method? (Choose
two.)
A. The hashCode method for a given class can be used to test for
object equality and object inequality for that class.
B. The hashCode method is used by the java.util.SortedSet collection
class to order the elements within that set.
C. The hashCode method for a given class can be used to test for
object inequality, but NOT object equality, for that class.
D. The only important characteristic of the values returned by a
hashCode method is that the distribution of values must follow a
Gaussian distribution.
E. The hashCode method is used by the java.util.HashSet collection
class to group the elements within that set into hash buckets for
swift retrieval.
Answer: CE
Question 173
Given:
enum Example { ONE, TWO, THREE }
Which is true?
A. The expressions (ONE == ONE) and ONE.equals(ONE) are both
guaranteed to be true.
B. The expression (ONE < TWO) is guaranteed to be true and
ONE.compareTo(TWO) is guaranteed to be less than one.
C. The Example values cannot be used in a raw java.util.HashMap;
instead, the programmer must use a java.util.EnumMap.
D. The Example values can be used in a java.util.SortedSet, but the
set will NOT be sorted because enumerated types do NOT implement
java.lang.Comparable.
Answer: A
Question 174
Click the Exhibit button.
1. import java.util.*;
2. class KeyMaster {
3. public int i;
4. public KeyMaster(int i) { this.i = i; }
5. public boolean equals(Object o) { return i == ((KeyMaster)o).i; }
6. public int hashCode() { return i; }
7. }
8. public class MapIt {
9. public static void main(String[] args) {
10. Set<KeyMaster> set = new HashSet<KeyMaster>();
11. KeyMaster k1 = new KeyMaster(1);
12. KeyMaster k2 = new KeyMaster(2);
13. set.add(k1); set.add(k1);
14. set.add(k2); set.add(k2);
15. System.out.print(set.size() + “:”);
16. k2.i = 1;
17. System.out.print(set.size() + “:”);
18. set.remove(k1);
19. System.out.print(set.size() + “:”);
20. set.remove(k2);
21. System.out.print(set.size());
22. }
23. }
What is the result?
A. 4:4:2:2
B. 4:4:3:2
C. 2:2:1:0
D. 2:2:0:0
E. 2:1:0:0
F. 2:2:1:1
G. 4:3:2:1
Answer: F
Question 175
Given:
1. import java.util.*;
2. public class Test {
3. public static void main(String[] args) {
4. List<String> strings = new ArrayList<String>();
5. // insert code here
6. }
7. }
Which four, inserted at line 5, will allow compilation to succeed?
(Choose four.)
A. String s = strings.get(0);
B. Iterator i1 = strings.iterator();
C. String[] array1 = strings.toArray();
D. Iterator<String> i2 = strings.iterator();
E. String[] array2 = strings.toArray(new String[1]);
F. Iterator<String> i3 = strings.iterator<String>();
Answer: ABDE
Question 176
Given:
1. import java.util.*;
2. public class Old {
3. public static Object get()(List list) {
4. return list.get(0);
5. }
6. }
Which three will compile successfully? (Choose three.)
A. Object o = Old.get0(new LinkedList());
B. Object o = Old.get0(new LinkedList<?>());
C. String s = Old.getfl(new LinkedList<String>());
D. Object o = Old.get0(new LinkedList<Object>());
E. String s = (String)Old.get0(new LinkedList<String>());
Answer: ADE
Question 177
Given:
11. public static void append(List list) { list.add(”0042”); }
12. public static void main(String[] args) {
13. List<Integer> intList = new ArrayList<Integer>();
14. append(intList);
15. System.out.println(intList.get(0));
16. }
‘What is the result?
A. 42
B. 0042
C. An exception is thrown at runtime.
D. Compilation fails because of an error in line 13.
E. Compilation fails because of an error in line 14.
Answer: B
Question 178
Given a pre-generics implementation of a method:
11. public static int sum(List list) {
12. int sum = 0;
13. for ( Iterator iter = list.iterator(); iter.hasNext(); ) {
14. int i = ((Integer)iter.next()).intValue();
15. sum += i;
16. }
17. return sum;
18. }
Which three changes must be made to the method sum to use
generics? (Choose three.)
A. remove line 14
B. replace line 14 with “int i = iter.next();”
C. replace line 13 with “for (int i : intList) {“
D. replace line 13 with “for (Iterator iter : intList) {“
E. replace the method declaration with “sum(List<int> intList)”
F. replace the method declaration with “sum(List<Integer> intList)”
Answer: ACF
Question 179
Given:
classA {}
class B extends A {}
class C extends A {}
class D extends B {}
Which three statements are true? (Choose three.)
A. The type List<A> is assignable to List.
B. The type List<B> is assignable to List<A>.
C. The type List<Object> is assignable to List<?>.
D. The type List<D> is assignable to List<? extends B>.
E. The type List<? extends A> is assignable to List<A>.
F. The type List<Object> is assignable to any List reference.
G. The type List<? extends B> is assignable to List<? extends A>.
Answer: CDG
Question 180
Given:
11. public void addStrings(List list) {
12. list.add(”foo”);
13. list.add(”bar”);
14. }
What must you change in this method to compile without warnings?
A. add this code after line 11:
list = (List<String>) list;
B. change lines 12 and 13 to:
list.add<String>(”foo”);
list.add<String>(”bar”);
C. change the method signature on line 11 to:
public void addStrings(List<? extends String> list) {
D. change the method signature on line 11 to:
public void addStrings(List<? super String> list) {
E. No changes are necessary. This method compiles without warnings.
Answer: D
Question 181
Given:
1. public class Test {
2. public <T extends Comparable> T findLarger(T x, T y) {
3. if(x.compareTo(y) > 0) {
4. return x;
5. } else {
6. return y;
7. }
8. }
9. }
and:
22. Test t = new Test();
23. // insert code here
Which two will compile without errors when inserted at line 23?
(Choose two.)
A. Object x = t.findLarger(123, “456”);
B. int x = t.findLarger(123, new Double(456));
C. int x = t.findLarger(123, new Integer(456));
D. int x = (int) t.findLarger(new Double(123), new Double(456));
Answer: AC
Question 182
Given:
11. // insert code here
12. private N min, max;
13. public N getMin() { return min; }
14. public N getMax() { return max; }
15. public void add(N added) {
16. if (min == null || added.doubleValue() <min.doubleValue())
17. min = added;
18. if (max == null ||added.doubleValue() > max.doubleValue())
19. max = added;
20. }
21. }
Which two, inserted at line 11, will allow the code to compile? (Choose
two.)
A. public class MinMax<?> {
B. public class MinMax<? extends Number> {
C. public class MinMax<N extends Object> {
D. public class MinMax<N extends Number> {
E. public class MinMax<? extends Object> {
F. public class MinMax<N extends Integer> {
Answer: DF
Question 183
A programmer must create a generic class MinMax and the type
parameter of MinMax must implement Comparable. Which
implementation of MinMax will compile?
A. class MinMax<E extends Comparable<E>> {
E min=null;
E max=null;
public MinMax() { }
public void put(E value) { /* store min or max */ }
}
B. class MinMax<E implements Comparable<E>> {
E min=null;
E max=null;
public MinMax() { }
public void put(E value) { /* store min or max */ }
}
C. class MinMax<E extends Comparable<E>> {
<E> E min = null;
<E> E max = null;
public MinMax() { }
public <E> void put(E value) { /* store min or max */ }
}
D. class MinMax<E implements Comparable<E>> {
<E> E min = null;
<E> E max = null;
public MinMax() { }
public <E> void put(E value) { /* store min or max */ }
}
Answer: A
Question 184
Given:
1. public class Drink implements Comparable {
2. public String name;
3. public int compareTo(Object o) {
4. return 0;
5. }
6. }
and:
20. Drink one = new Drink();
21. Drink two = new Drink();
22. one.name= “Coffee”;
23. two.name= “Tea”;
23. TreeSet set = new TreeSet();
24. set.add(one);
25. set.add(two);
A programmer iterates over the TreeSet and prints the name of each
Drink object.
What is the result?
A. Tea
B. Coffee
C. Coffee
Tea
D. Compilation fails.
E. The code runs with no output.
F. An exception is thrown at runtime.
Answer: B
Question 185
Given:
11. List list = // more code here
12. Collections.sort(list, new MyComparator());
Which code will sort this list in the opposite order of the sort in line
12?
A. Collections.reverseSort(list, new MyComparator());
B. Collections.sort(list, new MyComparator());
list.reverse();
C. Collections.sort(list, new InverseComparator(
new MyComparator()));
D. Collections.sort(list, Collections.reverseOrder(
new MyComparator()));
Answer: D
Question 186
Given:
int[] myArray=newint[] {1, 2,3,4, 5};
What allows you to create a list from this array?
A. List myList = myArray.asList();
B. List myList = Arrays.asList(myArray);
C. List myList = new ArrayList(myArray);
D. List myList = Collections.fromArray(myArray);
Answer: B
Question 187
Given:
13. public static void search(List<String> list) {
14. list.clear();
15. list.add(”b”);
16. list.add(”a”);
17. list.add(”c”);
18. System.out.println(Collections.binarySearch(list, “a”));
19. }
What is the result of calling search with a valid List implementation?
A. 0
B. 1
C. 2
D. a
E. b
F. c
G. The result is undefined.
Answer: G
Question 188
Given:
1. import java.util.*;
2.
3. public class LetterASort {
4. public static void main(String[] args) {
5. ArrayList<String> strings = new ArrayList<String>();
6. strings.add(’aAaA”);
7. strings.add(”AaA”);
8. strings.add(’aAa”);
9. strings.add(”AAaa”);
10. Collections.sort(strings);
11. for (String s: strings) { System.out.print(s + “ “); }
12. }
13. }
What is the result?
A. Compilation fails.
B. aAaA aAa AAaa AaA
C. AAaa AaA aAa aAaA
D. AaA AAaa aAaA aAa
E. aAa AaA aAaA AAaa
F. An exception is thrown at runtime.
Answer: C
Question 189
Given:
ArrayList a = new ArrayList();
containing the values {“1”, “2”, “3”, “4”, “5”, “6”, “7”, “8”}
Which code will return 2?
A. Collections. sort(a, a.reverse());
int result = Collections.binarySearch(a, “6”);
B. Comparator c = Collections.reverseOrder();
Collections.sort(a, c);
int result = Collections.binarySearch(a, “6”);
C. Comparator c = Collections.reverseOrder();
Collections.sort(a, c);
int result = Collections.binarySearch(a, “6”,c);
D. Comparator c = Collections.reverseOrder(a);
Collections.sort(a, c);
int result = Collections.binarySearch(a, “6”,c);
E. Comparator c = new InverseComparator(new Comparator());
Collections.sort(a);
int result = Collections.binarySearch(a, “6”,c);
Answer: C
Question 190
Given:
34. HashMap props = new HashMap();
35. props.put(”key45”, “some value”);
36. props.put(”key12”, “some other value”);
37. props.put(”key39”, “yet another value”);
38. Set s = props.keySet();
39. // insert code here
What, inserted at line 39, will sort the keys in the props HashMap?
A. Arrays.sort(s);
B. s = new TreeSet(s);
C. Collections.sort(s);
D. s = new SortedSet(s);
Answer: B
Question 191
Given classes defined in two different files:
1. package util;
2. public class BitUtils {
3. public static void process(byte[]) { /* more code here */ }
4. }
1. package app;
2. public class SomeApp {
3. public static void main(String[] args) {
4. byte[] bytes = new byte[256];
5. // insert code here
6. }
7. }
What is required at line 5 in class SomeApp to use the process method
of BitUtils?
A. process(bytes);
B. BitUtils.process(bytes);
C. util.BitUtils.process(bytes);
D. SomeApp cannot use methods in BitUtils.
E. import util.BitUtils.*; process(bytes);
Answer: C
Question
Given classes defined in two different files:
1. package util;
2. public class BitUtils {
3. private static void process(byte[] b) { }
4. }
1. package app;
2. public class SomeApp {
3. public static void main(String[] args) {
4. byte[] bytes = new byte[256];
5. // insert code here
6. }
7. }
What is required at line 5 in class SomeApp to use the process method
of BitUtils?
A. process(bytes);
B. BitUtils.process(bytes);
C. app.BitUtils.process(bytes);
D. util.BitUtils.process(bytes);
E. import util.BitUtils. *; process(bytes);
F. SomeApp cannot use the process method in BitUtils.
Answer: F
Question 193
Given classes defined in two different files:
1. package packageA;
2. public class Message {
3. String getText() { return “text”; }
4. }
and:
1. package packageB;
2. public class XMLMessage extends packageA.Message {
3. String getText() { return “<msg>text</msg>”; }
4. public static void main(String[] args) {
5. System.out.println(new XMLMessage().getText());
6. }
7. }
What is the result of executing XMLMessage.main?
A. text
B. <msg>text</msg>
C. An exception is thrown at runtime.
D. Compilation fails because of an error in line 2 of XMLMessage.
E. Compilation fails because of an error in line 3 of XMLMessage.
Answer: E
Question 194
Given a file GrizzlyBear.java:
1. package animals.mammals;
2.
3. public class GrizzlyBear extends Bear {
4. void hunt() {
5. Salmon s = findSalmon();
6. s.consume();
7. }
8. }
and another file, Salmon.java:
1. package animals.fish;
2.
3. public class Salmon extends Fish {
4. void consume() { /* do stuff */ }
5. }
Assume both classes are defined in the correct directories for theft
packages, and that the Mammal class correctly defines the
findSalmon() method. Which two changes allow this code to compile
correctly? (Choose two.)
A. add public to the start of line 4 in Salmon.java
B. add public to the start of line 4 in GrizzlyBear.java
C. add import animals.mammals.*; at line 2 in Salmon.java
D. add import animals.fish.*; at line 2 in GrizzlyBear.java
E. add import animals.fish.Salmon.*; at line 2 in GrizzlyBear.java
F. add import animals.mammals.GrizzlyBear.*;at line 2 in Salmon.java
Answer: AD
Question 195
Given a class Repetition:
1. package utils;
2.
3. public class Repetition {
4. public static String twice(String s) { return s + s; }
5. }
and given another class Demo:
1. // insert code here
2.
3. public class Demo {
4. public static void main(String[] args) {
5. System.out.println(twice(”pizza”));
6. }
7. }
Which code should be inserted at line 1 of Demo.java to compile and
run Demo to print “pizzapizza”?
A. import utils.*;
B. static import utils.*;
C. import utils.Repetition.*;
D. static import utils.Repetition. *;
E. import utils.Repetition.twice();
F. import static utils.Repetition.twice;
G. static import utils.Repetition.twice;
Answer: F
Question 196
Given:
11. interface DeclareStuff{
12. public static final int EASY = 3;
13. void doStuff(int t); }
14. public class TestDeclare implements DeclareStuff {
15. public static void main(String [] args) {
16. int x=5;
17. new TestDeclare().doStuff(++x);
18. }
19. void doStuff(int s) {
20. s += EASY + ++s;
21. System.out.println(”s “ + s);
22. }
23. }
What is the result?
A. s 14
B. s 16
C. s 10
D. Compilation fails.
E. An exception is thrown at runtime.
Answer: D
Question 197
Given:
1. interface DoStuff2 {
2. float getRange(int low, int high); }
3.
4. interface DoMore {
5. float getAvg(int a, int b, int c); }
6.
7. abstract class DoAbstract implements DoStuff2, DoMore { }
8.
9. class DoStuff implements DoStuff2 {
10. public float getRange(int x, int y) { return 3.14f; } }
11.
12. interface DoAll extends DoMore {
13. float getAvg(int a, int b, int c, int d); }
What is the result?
A. The file will compile without error.
B. Compilation fails. Only line 7 contains an error.
C. Compilation fails. Only line 12 contains an error.
D. Compilation fails. Only line 13 contains an error.
E. Compilation fails. Only lines 7 and 12 contain errors.
F. Compilation fails. Only lines 7 and 13 contain errors.
G. Compilation fails. Lines 7, 12, and 13 contain errors.
Answer: A
Question 198
Given:
11. public class Counter {
12. public static void main(String[] args) {
13. int numArgs = /* insert code here */;
14. }
15. }
and the command line:
java Counter one fred 42
Which code, inserted at line 13, captures the number of arguments
passed into the program?
A. args.count
B. args.length
C. args.count()
D. args.length()
E. args.getLength()
Answer: B
Question 199
Given a correctly compiled class whose source code is:
1. package com.sun.sjcp;
2. public class Commander {
3. public static void main(String[] args) {
4. // more code here
5. }
6. }
Assume that the class file is located in /foo/com/sun/sjcp/, the current
directory is /foo/, and that the classpath contains “.“ (current
directory).
Which command line correctly runs Commander?
A. java Commander
B. java com. sim. sjcp.Commander
C. java com/sun/sjcp/Commander
D. java -cp com.sun.sjcp Commander
E. java -cp com/sun/sjcp Commander
Answer: B
Question 200
Given the command line java Pass2 and:
15. public class Pass2 {
16. public void main(String [] args) {
17.int x=6;
18. Pass2 p = new Pass2();
19. p.doStuff(x);
20. System.out.print(” main x = “+ x);
21. }
22.
23. void doStuff(int x) {
24. System.out.print(” doStuffx = “+ x++);
25. }
26. }
What is the result?
A. Compilation fails.
B. An exception is thrown at runtime.
C. doStuffx = 6 main x = 6
D. doStuffx = 6 main x = 7
E. doStuffx = 7 main x = 6
F. doStuffx = 7 main x = 7
Answer: B
Question 201
Given:
15. public class Yippee {
16. public static void main(String [] args) {
17. for(int x = 1; x < args.length; x++) {
18. System.out.print(args[x] +“ “);
19. }
20. }
21. }
and two separate command line invocations:
java Yippee
java Yippee 1234
What is the result?
A. No output is produced.
123
B. No output is produced.
234
C. No output is produced.
1234
D. An exception is thrown at runtime.
123
E. An exception is thrown at runtime.
234
F. An exception is thrown at rijntime.
1234
Answer: B
Question 202
Given:
12. public class Yippee2 {
13.
14. static public void main(String [] yahoo) {
15. for(int x= 1; x<yahoo.length; x++) {
16. System.out.print(yahoo[x] + “ “);
17. }
18. }
19. }
and the command line invocation:
java Yippee2 a b c
What is the result?
A.a b
B.b c
C.a b c
D. Compilation fails.
E. An exception is thrown at runtime.
Answer: B
Question 203
Given:
11. public class Commander {
12. public static void main(String[] args) {
13. String myProp = /* insert code here */
14. System.out.println(myProp);
15. }
16. }
and the command line:
java -Dprop.custom=gobstopper Commander
Which two, placed on line 13, will produce the output gobstopper?
(Choose two.)
A. System.load(”prop.custom”);
B. System.getenv(”prop.custom”);
C. System.property(”prop.custom”);
D. System.getProperty(”prop.custom”);
E. System.getProperties().getProperty(”prop.custom”);
Answer: DE
Question 204
Click the Exhibit button.
11. class Payload {
12. private int weight;
13. public Payload(int wt) { weight = wt; }
13. public void setWeight(mt w) { weight = w; }
15. public String toString { return Integer.toString(weight); }
16. }
17.
18. public class TestPayload {
19. static void changePayload(Payload p) {
20. /* insert code here */
21. }
22.
23. public static void main(String[] args) {
24. Payload p = new Payload();
25. p.setWeight(1024);
26. changePayload(p);
27. System.out.println(”The value of p is “+ p);
28. }
29. }
Which statement, placed at line 20, causes the code to print “The
value of p is 420.”?
A. p.setWeight(420);
B. p.changePayload(420);
C. p = new Payload(420);
D. Payload.setWeight(420);
E. p = Payload.setWeight(420);
F. p = new Payload();
p.setWeight(420);
Answer: A
Question 205
Click the Exhibit button.
1. public class Item {
2. private String desc;
3. public String getDescription() { return desc; }
4. public void setDescription(String d) { desc = d; }
5.
6. public static void modifyDesc(Item item, String desc) {
7. item = new Item();
8. item.setDescription(desc);
9. }
10. public static void main(String[] args) {
11. Item it = new Item();
12. it.setDescription(”Gobstopper”);
13. Item it2 = new Item();
14. it2.setDescription(”Fizzylifting”);
15. modifyDesc(it, “Scrumdiddlyumptious”);
16. System.out.println(it.getDescription());
17. System.out.println(it2.getDescription());
18. }
19. }
What is the outcome of the code?
A. Compilation fails.
B. Gobstopper
Fizzylifting
C. Gobstopper
Scrumdiddlyumptious
D. Scrumdiddlyumptious
Fizzylifltng
E. Scrumdiddlyumptious
Scrumdiddlyumptious
Answer: B
Question 206
Given:
11. public class ItemTest {
12. private final mt id;
13. public ItemTest(int id) { this.id = id; }
14. public void updateId(int newId) { id = newId; }
15.
16. public static void main(String[] args) {
17. ItemTest fa = new ItemTest(42);
18. fa.updateId(69);
19. System.out.println(fa.id);
20. }
21. }
What is the result?
A. Compilation fails.
B. An exception is thrown at runtime.
C. The attribute id in the Item object remains unchanged.
D. The attribute id in the Item object is modified to the new value.
E. A new Item object is created with the preferred value in the id
attribute.
Answer: A
Question 207
Click the Exhibit button.
10. class Inner {
11. private int x;
12. public void setX( int x) { this.x = x; }
13. public int getX() { return x; }
14. }
15.
16. class Outer {
17. private Inner y;
18. public void setY( Inner y) { this.y = y; }
19. public Inner getY() { return y; }
20. }
21.
22. public class Gamma {
23. public static void main( String[] args) {
24. Outer o = new Outer();
25. Inner i = new Inner();
26.int n=10;
27. i.setX(n);
28. o.setY(i);
29. // insert code here
30. System.out.println( o.getY().getX());
31. }
32. }
Which three code fragments, added individually at line 29, produce the
output 100? (Choose three.)
A. n = 100;
B. i.setX( 100);
C. o.getY().setX( 100);
D. i = new Inner(); i.setX( 100);
E. o.setY( i); i = new Inner(); i.setX( 100);
F. i = new Inner(); i.setX( 100); o.setY( i);
Answer: BCF
Question 208
Click the Exhibit button.
10. class Foo {
11. private int x;
12.publicFoo(intx) {this.x=x; }
13. public void setX( int x) { this.x = x; }
14. public int getX() { return x; }
15. }
16.
17. public class Gamma {
18.
19. static Foo fooBar( Foo foo) {
20. foo = new Foo( 100);
21. return foo;
22. }
23.
24. public static void main( String[] args) {
25. Foo foo = new Foo( 300);
26. System.out.print( foo.getX() + “-“);
27.
28. Foo fooFoo = fooBar( foo);
29. System.out.print( foo.getX() + “-“);
30. System.out.print( fooFoo.getX() + “-“);
31.
32. foo = fooBar( fooFoo);
33. System.out.print( foo.getX() + “-“);
34. System.out.prmt( fooFoo.getX());
35. }
36. }
What is the output of this program?
A. 300-100-100-100-100
B. 300-300-100-100-100
C. 300-300-300-100-100
D. 300-300-300-300-100
Answer: B
Question 209
Given:
11. public void genNumbers() {
12. ArrayList numbers = new ArrayList();
13. for (int i=0; i<10; i++) {
14. int value = i * ((int) Math.random());
15. Integer intObj = new Integer(value);
16. numbers.add(intObj);
17. }
18. System.out.println(numbers);
19. }
Which line of code marks the earliest point that an object referenced
by intObj becomes a candidate for garbage collection?
A. Line 16
B. Line 17
C. Line 18
D. Line 19
E. The object is NOT a candidate for garbage collection.
Answer: D
Question 210
Given:
11. rbo = new ReallyBigObject();
12. // more code here
13. rbo = null;
14. /* insert code here */
Which statement should be placed at line 14 to suggest that the virtual
machine expend effort toward recycling the memory used by the
object rbo?
A. System.gc();
B. Runtime.gc();
C. System.freeMemory();
D. Runtime.getRuntime().growHeap();
E. Runtime.getRuntime().freeMemory();
Answer: A
Question 211
Given:
11. class Snoochy {
12. Boochybooch;
13. public Snoochy() { booch = new Boochy(this); }
14. }
15.
16. class Boochy {
17. Snoochy snooch;
18. public Boochy(Snoochy s) { snooch = s; }
19. }
And the statements:
21. public static void main(String[] args) {
22. Snoochy snoog = new Snoochy();
23. snoog = null;
24. // more code here
25. }
Which statement is true about the objects referenced by snoog,
snooch, and booch immediately after line 23 executes?
A. None of these objects are eligible for garbage collection.
B. Only the object referenced by booch is eligible for garbage
collection.
C. Only the object referenced by snoog is eligible for garbage
collection.
D. Only the object referenced by snooch is eligible for garbage
collection.
E. The objects referenced by snooch and booch are eligible for garbage
collection.
Answer: E
Question 212
Given:
1. public class GC {
2. private Object o;
3. private void doSomethingElse(Object obj) { o = obj; }
4. public void doSomething() {
5. Object o = new Object();
6. doSomethingElse(o);
7. o = new Object();
8. doSomethingElse(null);
9.o=null;
10. }
11. }
When the doSomething method is called, after which line does the
Object created in line 5 become available for garbage collection?
A. Line 5
B. Line 6
C. Line 7
D. Line 8
E. Line 9
F. Line 10
Answer: D
Question 213
Which two are true? (Choose two.)
A. A finalizer may NOT be invoked explicitly.
B. The finalize method declared in class Object takes no action.
C. super.finalize() is called implicitly by any overriding finalize method.
D. The finalize method for a given object will be called no more than
once by the garbage collector.
E. The order in which finalize will be called on two objects is based on
the order in which the two objects became finalizable.
Answer: BD
Question 214
A class games.cards.Poker is correctly defined in the jar file Poker.jar.
A user wants to execute the main method of Poker on a UNIX system
using the command:
java games.cards.Poker
What allows the user to do this?
A. put Poker.jar in directory /stuff/java, and set the CLASSPATH to
include /stuff/java
B. put Poker.jar in directory /stuff/java, and set the CLASSPATH to
include /stuff/java/*.jar
C. Put Poker.jar in directory /stuff/java, and set the CLASSPATH to
include /stuff/java/Poker.jar
D. put Poker.jar in directory /stuff/java/games/cards, and set the
CLASSPATH to include /stuff/java
E. put Poker.jar in directory /stuff/java/games/cards, and set the
CLASSPATH to include /stuffijava/*.jar
F. put Poker.jar in directory /stuff/java/games/cards, and set the
CLASSPATH to include /stuff/java/Poker.jar
Answer: C
Question 215
Click the Exhibit button.
Given the fully-qualified class names:
com.foo.bar.Dog
com.foo.bar.blatz.Book
com.bar.Car
com.bar.blatz.Sun
Which graph represents the correct directory structure for a JAR file
from which those classes can be used by the compiler and JYM?
A. Jar A
B. Jar B
C. Jar C
D. Jar D
E. Jar E
Answer: A
Question 216
A developer is creating a class Book that needs to access class Paper.
The Paper class is deployed in a JAR named myLib.jar. Which three,
taken independently, will allow the developer to use the Paper class
while compiling the Book class? (Choose three.)
A. The JAR file is located at $JAVA_HOME/jre/classes/myLib.jar.
B. The JAR file is located at $JAVA_HOME/jre/lib/ext/myLib.jar.
C. The JAR file is located at /foo/myLib.jar and a classpath
environment variable is set that includes /foo/myLib.jar/Paper.class.
D. The JAR file is located at /foo/myLib.jar and a classpath
environment variable is set that includes /foo/myLib.jar.
E. The JAR file is located at /foo/myLib.jar and the Book class is
compiled using javac -cp /foo/myLib.jar/Paper Book.java.
F. The JAR file is located at /foo/myLib.jar and the Book class is
compiled using javac -d /foo/myLib.jar Book.java.
G. The JAR file is located at /foo/myLib.jar and the Book class is
compiled using javac -classpath /foo/myLib.jar Book.java.
Answer: BDG
Question 217
Given:
1. package com.company.application;
2.
3. public class MainClass {
4. public static void main(String[] args) { }
5. }
And MainClass exists in the /apps/com/company/application directory.
Assume the CLASSPATH environment variable is set to “.“ (current
directory). Which two java commands entered at the command line
will run MainClass? (Choose two.)
A. java MainClass if run from the /apps directory
B. java com.company.application.MainClass if run from the /apps
directory
C. java -classpath /apps com.company.application.MainClass if run
from any directory
D. java -classpath . MainClass if run from the
/apps/com/company/application directory
E. java -classpath /apps/com/company/application:. MainClass if run
from the /apps directory
F. java com.company.application.MainClass if run from the
/apps/com/company/application directory
Answer: BC
Question 218
A UNIX user named Bob wants to replace his chess program with a
new one, but he is hot sure where the old one is installed. Bob is
currently able to run a Java chess program starting from his home
directory /home/bob using the command:
java -classpath /test:/home/bob/downloads/* .jar games.Chess
Bob’s CLASSPATH is set (at login time) to:
/usr/lib:/home/bob/classes:/opt/java/lib:/opt/java/lib/* .jar
What is a possible location for the Chess.class file?
A. /test/Chess.class
B. /home/bob/Chess.class
C. /test/games/Chess.class
D. /usr/lib/games/Chess.class
E. /home/bob/games/Chess.class
F. inside jarfile /opt/java/lib/Games.jar (with a correct manifest)
G. inside jarfile /home/bob/downloads/Games.jar (with a correct
manifest)
Answer: C
Question 219
Given:
11. public static void test(String str) {
12. if(str == null | str.lellgth() == 0) {
13. System.out.println(”String is empty”);
14. } else {
15. System.out.println(”String is not empty”);
16. }
17. }
And the invocation:
31. test(llull);
What is the result?
A. Au exception is thrown at runtime.
B. “String is empty” is printed to output.
C. Compilation fails because of au error in line 12.
D. “String is not empty” is printed to output.
Answer: A
Question 220
Given:
11. public static void test(String str) {
12. int check = 4;
13. if (check = str.length()) {
14. System.out.print(str.charAt(check -= 1) +“, “);
15. } else {
16. System.out.print(str.charAt(0) + “, “);
17. }
18. }
and the invocation:
21. test(”four”);
22. test(”tee”);
23. test(”to”);
What is the result?
A. r, t, t,
B. r, e, o,
C. Compilation fails.
D. An exception is thrown at runtime.
Answer: C
Question 221
Given:
10. public class MyClass {
11.
12. public Integer startingI;
13. public void methodA() {
14. Integer i = new Integer(25);
15. startingI = i;
16. methodB(i);
17. }
18. private void methodB(Integer i2) {
19. i2 = i2.intValue();
20.
21. }
22. }
If methodA is invoked, which two are true at line 20? (Choose two.)
A. i2 == startingI returns true.
B. i2 == startingI returns false.
C. i2.equals(startingI) returns true.
D. i2.equals(startingI) returns false.
Answer: BC
Question 222
222. Given:
11. class Cup { }
12. class PoisonCup extends Cup { }
21. public void takeCup(Cup c) {
22. if(c instanceof PoisonCup) {
23. System.out.println(”Inconceivable!”);
24. } else if(c instanceof Cup) {
25. System.out.println(”Dizzying intellect!”);
26. } else {
27. System.exit(0);
28. }
29. }
And the execution of the statements:
Cup cup = new PoisonCup();
takeCup(cup);
What is the output?
A. Inconceivable!
B. Dizzying intellect!
C. The code runs with no output.
D. An exception is thrown at runtime.
E. Compilation fails because of an error in line 22.
Answer: A
Question 223
Given:
11. String[] elements = { “for”, “tea”, “too” };
12. String first = (elements.length > 0)? elements[0] null;
What is the result?
A. Compilation fails.
B. An exception is thrown at runtime.
C. The variable first is set to null.
D. The variable first is set to elements[0].
Answer: D
Question 224
Given:
42. public class ClassA {
43. public int getValue() {
44.int value=0;
45. boolean setting = true;
46. String title=”Hello”;
47. if (value || (setting && title == “Hello”)) { return 1; }
48. if (value == 1 & title.equals(”Hello”)) { return 2; }
49. }
50. }
And:
70. ClassA a = new ClassA();
71. a.getValue();
What is the result?
A. 1
B. 2
C. Compilation fails.
D. The code runs with no output.
E. An exception is thrown at runtime.
Answer: C