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.
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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();
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.
class Foo {
private int x;
publicFoo(intx) {this.x=x; }
public void setX( int x) { this.x = x; }
public int getX() { return x; }
}
public class Gamma {
static Foo fooBar( Foo foo) {
foo = new Foo( 100);
return foo;
}
public static void main( String[] args) {
Foo foo = new Foo( 300);
System.out.print( foo.getX() + “-“);
Foo fooFoo = fooBar( foo);
System.out.print( foo.getX() + “-“);
System.out.print( fooFoo.getX() + “-“);
foo = fooBar( fooFoo);
System.out.print( foo.getX() + “-“);
System.out.prmt( fooFoo.getX());
}
}
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
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?()
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);
public class ItemTest {
private final mt id;
public ItemTest(int id) { this.id = id; }
public void updateId(int newId) { id = newId; }
public static void main(String[] args) {
ItemTest fa = new ItemTest(42);
fa.updateId(69);
System.out.println(fa.id);
}
}
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.
public class Item {
private String desc;
public String getDescription() { return desc; }
public void setDescription(String d) { desc = d; }
public static void modifyDesc(Item item, String desc) {
item = new Item();
item.setDescription(desc);
}
public static void main(String[] args) {
Item it = new Item();
it.setDescription(”Gobstopper”);
Item it2 = new Item();
it2.setDescription(”Fizzylifting”);
modifyDesc(it, “Scrumdiddlyumptious”);
System.out.println(it.getDescription());
System.out.println(it2.getDescription());
}
}
What is the outcome of the code? ()
A. Compilation fails.
B. Gobstopper Fizzylifting
C. Gobstopper Scrumdiddlyumptious
D. Scrumdiddlyumptious Fizzylifltng
E. Scrumdiddlyumptious Scrumdiddlyumptious
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);
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?()
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”);
public class Yippee2 {
static public void main(String [] yahoo) {
for(int x= 1; x
}
}
}
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.
public class Yippee {
public static void main(String [] args) {
for(int x = 1; x < args.length; x++) {
System.out.print(args[x] +“ “);
}
}
}
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
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