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Sun Certification Interview Questions And Answers

Certifications :: Sun Certified Java Developer Job Interview Questions and Answers

Sun Certified Java Developer Frequently Asked Questions in various Sun Certified Java Developer Interviews asked by the interviewer. So learn Sun Certified Java Developer with the help of this Sun Certified Java Developer Interview questions and answers guide and feel free to comment as your suggestions, questions and answers on any Sun Certified Java Developer Interview Question or answer by the comment feature available on the page.

1 ► Explain What is the result of mounting a file system with thenoatimeoption enabled?A.It enables the UFS loggingB.It disables the update of file access timesC.It prevents the creation of files larger than 2GbytesD.It prevents the user from updating the file modification times
2 ► Explain 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>; }
3 ► Explain 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 classB. only the Target classC. any class in the test packageD. any class that extends Target
4 ► Explain 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.
5 ► Explain Given:11. public class Rainbow {12. public enum MyColor {13. RED(0xff0000), GREEN(0x00ff00), BLUE(0x0000ff);14. private final int rgb;15. MyColor(int rgb) { this.rgb = rgb; }16. public int getRGB() { return rgb; }17. };18. public static void main(String[] args) {19. // insert code here20. }21. }Which code fragment, inserted at line 19, allows the Rainbow class to compile?A. MyColor skyColor = BLUE;B. MyColor treeColor = MyColor.GREEN;C. if(RED.getRGB() < BLUE.getRGB()) { }D. Compilation fails due to other error(s) in the code.E. MyColor purple = new MyColor(0xff00ff);F. MyColor purple = MyColor.BLUE + MyColor.RED;
6 ► Explain 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); }
7 ► Explain Which two statements are true? (Choose two.)A. It is possible for more than two threads to deadlock at once.B. The JVM implementation guarantees that multiple threads cannot enter into a deadlocked state.C. Deadlocked threads release once their sleep() methods sleep duration has expired.D. Deadlocking can occur only when the wait(), notify(), and notifyAll() methods are used incorrectly.E. It is possible for a single-threaded application to deadlock if synchronized blocks are used incorrectly.F. If a piece of code is capable of deadlocking, you cannot eliminate the possibility of deadlocking by insertinginvocations of Thread.yield().
8 ► Tell me What is native keyword and abstract keyword?
9 ► Explain Given:1. public class Blip {2. protected int blipvert(int x) { return 0; }3. }4. class Vert extends Blip {5. // insert code here6. }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; }
10 ► Explain 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, 0B. 150, 60, 0C. Compilation fails.D. 150, 150, 150E. An exception is thrown at runtime.
11 ► 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: ProblemB. run.java.lang.RuntimeException: ProblemC. End of method.java.lang.RuntimeException: ProblemD. End of method.run.java.lang.RuntimeException: ProblemE. run.java.lang.RuntimeException: ProblemEnd of method.
12 ► Suppose A team of programmers is reviewing a proposed API for a new utility class. After some discussion, they realizethat they can reduce the number of methods in the API without losing any functionality. If they implement thenew design, which two OO principles will they be promoting?A. Looser couplingB. Tighter couplingC. Lower cohesionD. Higher cohesionE. Weaker encapsulationF. Stronger encapsulation
13 ► 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. 0.0B. Compilation fails.C. A ParseException is thrown by the parse method at runtime.D. A NumberFormatException is thrown by the parse method at runtime.
14 ► 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 */ }
15 ► 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 graniteC. granite graniteD. atom granite graniteE. An exception is thrown at runtime.F. atom granite atom granite
16 ► Explain Given:10. class Nav{11. public enum Direction { NORTH, SOUTH, EAST, WEST }12. }13. public class Sprite{14. // insert code here15. }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;
17 ► Explain IF you are remotely logged on to a Solaris machine, What command would you execute?
18 ► 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. CanadaB. null CanadaC. Canada nullD. Canada CanadaE. Compilation fails due to an error on line 26.F. Compilation fails due to an error on line 29.
19 ► 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 5-2B. The output could be 6-1 6-2 5-1 5-2C. The output could be 6-1 5-2 6-2 5-1D. The output could be 6-1 6-2 5-1 7-1