JAVA Concepts

Which of these keywords is not a part of exception handling?

• try

• finally

• thrown

• catch

What will be the output of the following Java program?

1. class exception_handling

2. {

3. public static void main(String args[])

4. {

5. try

6. {

7. System.out.print("Hello" + " " + 1 / 0);

8. }

9. catch(ArithmeticException e)

10. {

11. System.out.print("World");

12. }

13. }

14. }

15. 
    

• 1. Hello

• 1. World

• 1. HelloWorld

• 1. Hello World

What will be the output of the following Java program?

1. class exception_handling

2. {

3. public static void main(String args[])

4. {

5. try

6. {

7. int a, b;

8. b = 0;

9. a = 5 / b;

10. System.out.print("A");

11. }

12. catch(ArithmeticException e)

13. {

14. System.out.print("B");

15. }

16. finally

17. {

18. System.out.print("C");

19. }

20. }

21. }

• A

• B

• AC

• BC

Which principle allows different classes to be treated as instances of the same class through inheritance?

• Encapsulation

• Abstraction

• Inheritance

• Polymorphism

In Java, what concept allows us to implement runtime polymorphism?

• Method overloading

• Method overriding

• Constructors

• Static methods

Which of these allows compile-time polymorphism?

• Method overloading

  
  

• Method overriding

• Both

• None of the above

In which scenario does Java NOT allow polymorphism?

• When overriding private methods

• When using the method overloading

• When using interface methods

• When using abstract methods

Which of this keyword must be used to inherit a class?

• super

• this

• extent

• extends

Which of these is correct way of inheriting class A by class B?
a) class B + class A {}
b) class B inherits class A {}
c) class B extends A {}
d) class B extends class A {}

• class B + class A {}

• class B inherits class A {}

• class B extends A {}

• class B extends class A {}

What will be the output of the following Java program?

1. class A

2. {

3. int i;

4. }

5. class B extends A

6. {

7. int j;

8. void display()

9. {

10. super.i = j + 1;

11. System.out.println(j + " " + i);

12. }

13. }

14. class inheritance

15. {

16. public static void main(String args[])

17. {

18. B obj = new B();

19. obj.i=1;

20. obj.j=2;

21. obj.display();

22. }

23. }

• 2 2

• 3 3

• 2 3

• 3 2