Discussion
Home ‣ Interview ‣ Technology Comments
- Question
Which among the following is a scope resolution operator?
Options- A. :
- B. ::
- C. :?
- D. None
- Correct Answer
- ::
Explanation:: is the scope resolution operator
- 1. Why interface method is always public? Discuss
- 2. Which of the following method declarations are allowed inside interface?
Options- A. public void m1()
- B. private void m1()
- C. protected void m1()
- D. abstract public void m1() Discuss
- 3. Inside an interface when should the variables be initialized?
Options- A. Globally
- B. Whenever required
- C. Inside a function
- D. During the time of declaration Discuss
- 4. Which of the following statements are equal for a variable declared in the interface ? 1. int X=10 2. public int X=10 3. public static final int X=10
Options- A. Only 1 and 2 are equal
- B. Only 2 and 3 are equal
- C. All are unequal
- D. All are equal Discuss
- 5. What is the difference between an Interface and an Abstract class ? Discuss
- 6. Which kind of inheritance is not supported directly through classes in java?
Options- A. Multilevel
- B. Multiple
- C. Single
- D. Hirarcheal Discuss
- 7. public class Threads2 implements Runnable { public void run() { System.out.println("run."); throw new RuntimeException("Problem"); Which among the following is true? } public static void main(String[] args) { Thread t = new Thread(new Threads2()); t.start(); System.out.println("End of method."); } }
Options- 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 Discuss
- 8. 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; } } Which two classes use the Shape class correctly?
Options- 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. None Discuss
- 9. 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; } } Which two classes use the Shape class correctly?
Options- 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. None Discuss
- 10. X implements Y, Z Arguments: 1. X should be class 2. Y, Z should be interfaces
Options- A. Only 1 is true
- B. Only 2 is true
- C. Both 1 and 2 are true
- D. None Discuss
Technology problems
Search Results
Correct Answer: To make this method available to every implementation class
Correct Answer: abstract public void m1()
Explanation:
Inside an interface every method will be by default abstract and public
Correct Answer: During the time of declaration
Explanation:
They should be initialized during the time of declaration itself otherwise it is a compilation eror
Correct Answer: All are equal
Explanation:
All the statements are equal because inside an interface a variable declared will be public static final by default
Correct Answer: 1Main difference is methods of a Java interface are implicitly abstract and cannot have implementations A Java abstract class can have instance methods that implements a default behavior 2Variables declared in a Java interface is by default final An abstract class may contain non-final variables 3Members of a Java interface are public by default A Java abstract class can have the usual flavors of class members like private, protected, etc 4Java interface should be implemented using keyword ?implements?; A Java abstract class should be extended using keyword ?extends? 5An interface can extend another Java interface only, an abstract class can extend another Java class and implement multiple Java interfaces 6A Java class can implement multiple interfaces but it can extend only one abstract class 7Interface is absolutely abstract and cannot be instantiated; A Java abstract class also cannot be instantiated, but can be invoked if a main() exists 8In comparison with java abstract classes, java interfaces are slow as it requires extra indirection
Correct Answer: Multiple
Explanation:
Multiple inheritance is not supported directly but it is achieved through the concept of Interface
Correct Answer: End of method. run. java.lang.RuntimeException: Problem
Explanation:
Only D can be true
Correct Answer: public abstract class Circle extends Shape { private int radius; }
Explanation:
Only B is true
Correct Answer: public abstract class Circle extends Shape { private int radius; }
Explanation:
Only B is true
Correct Answer: Both 1 and 2 are true
Explanation:
Both the statements are true
Comments
There are no comments.More in Interview:
Programming
Copyright ©CuriousTab. All rights reserved.