Top Sun Certification Interview Questions & Answers:

1. Public abstract class shape {
private int x;
private int y;
public abstract void draw();
public void setanchor(int x, int y) {
this.x = x;
this.y = y;
}
}
give a explanation about this code?

2. Explain Given:
11. class PingPong2 {
12. synchronized void hit(long n) {
13. for(int i = 1; i < 3; i++)
14. System.out.print(n + "-" + i + " ");
15. }
16. }
17. public class Tester implements Runnable {
18. static PingPong2 pp2 = new PingPong2();
19. public static void main(String[] args) {
20. new Thread(new Tester()).start();
21. new Thread(new Tester()).start();
22. }
23. public void run() { pp2.hit(Thread.currentThread().getId()); }
24. }
Which statement is true?
A. The output could be 5-1 6-1 6-2 5-2
B. The output could be 6-1 6-2 5-1 5-2
C. The output could be 6-1 5-2 6-2 5-1
D. The output could be 6-1 6-2 5-1 7-1

B:The output could be 6-1 6-2 5-1 5-2

3. Explain Given:
21. class Money {
22. private String country = "Canada";
23. public String getC() { return country; }
24. }
25. class Yen extends Money {
26. public String getC() { return super.country; }
27. }
28. public class Euro extends Money {
29. public String getC(int x) { return super.getC(); }
30. public static void main(String[] args) {
31. System.out.print(new Yen().getC() + " " + new Euro().getC());
32. }
33. }
What is the result?
A. Canada
B. null Canada
C. Canada null
D. Canada Canada
E. Compilation fails due to an error on line 26.
F. Compilation fails due to an error on line 29.

E:Compilation fails due to an error on line 26.

4. Explain IF you are remotely logged on to a Solaris machine, What command would you execute?

mt f /dev/rmt/0 status

5. Explain 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;

D:Nav.Direction d = Nav.Direction.NORTH;

6. Explain Given:
5. class Atom {
6. Atom() { System.out.print("atom "); }
7. }
8. class Rock extends Atom {
9. Rock(String type) { System.out.print(type); }
10. }
11. public class Mountain extends Rock {
12. Mountain() {
13. super("granite ");
14. new Rock("granite ");
15. }
16. public static void main(String[] a) { new Mountain(); }
17. }
What is the result?
A. Compilation fails.
B. atom granite
C. granite granite
D. atom granite granite
E. An exception is thrown at runtime.
F. atom granite atom granite

F:atom granite atom granite

7. Explain 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 */ }

B:public abstract class Circle extends Shape {
private int radius;
}
E:public class Circle extends Shape {
private int radius;
public void draw() {/* code here */}

8. Explain 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.

B:Compilation fails.

9. Suppose A team of programmers is reviewing a proposed API for a new utility class. After some discussion, they realize
that they can reduce the number of methods in the API without losing any functionality. If they implement the
new design, which two OO principles will they be promoting?
A. Looser coupling
B. Tighter coupling
C. Lower cohesion
D. Higher cohesion
E. Weaker encapsulation
F. Stronger encapsulation

A:Looser coupling

10. Explain Given:
1. public class Threads2 implements Runnable {
2.
3. public void run() {
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.

D:End of method.
run.
java.lang.RuntimeException: Problem
E:run.
java.lang.RuntimeException: Problem
End of method.