Java Quiz

Who invented Java Programming?

• Guido van Rossum

• Dennis Ritchie

• Bjarne Stroustrup

• James Gosling

Which one of the following is not a Java feature?

• Object-oriented

• Dynamic and Extensible

• Portable
  

• Use of pointers

Answer explanation

Pointers is not a Java feature. Java provides an efficient abstraction layer for developing without using a pointer in Java. Features of Java Programming are Portable, Architectural Neutral, Object-Oriented, Robust, Secure, Dynamic and Extensible, etc.

Which of these cannot be used for a variable name in Java?

• identifier & keyword

• identifier

• none of the mentioned

• keyword

Answer explanation

Keywords are specially reserved words that can not be used for naming a user-defined variable, for example: class, int, for, etc.

What will be the output of the following Java code?

class increment {

public static void main(String args[])

{

int g = 3;

System.out.print(++g * 8);

}

}

• 32
  

• 33

• 25

• 24

Answer explanation

Operator ++ has more preference than *, thus g becomes 4 and when multiplied by 8 gives 32.
output:

1. class output {

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

3. {

4. double a, b,c;

5. a = 3.0/0;

6. b = 0/4.0;

7. c=0/0.0;

8.  

9. System.out.println(a);

10. System.out.println(b);

11. System.out.println(c);

• NaN

• Infinity

• 0.0

• all of the mentioned

Answer explanation

For floating point literals, we have constant value to represent (10/0.0) infinity either positive or negative and also have NaN (not a number for undefined like 0/0.0), but for the integral type, we don’t have any constant that’s why we get an arithmetic exception.

Which of the following is a type of polymorphism in Java Programming?

• Multiple polymorphism

• Compile Time Polymorphism

• Mulitilevel Polymorphism

• Execution time polymorphism

Answer explanation

There are two types of polymorphism in Java. Compile time polymorphism (overloading) and runtime polymorphism (overriding).

What will be the output of the following Java program?

1. class leftshift_operator

2. {

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

4. {

5. byte x = 64;

6. int i;

7. byte y;

8. i = x << 2;

9. y = (byte) (x << 2);

10. System.out.print(i + " " + y);

• 0 256

• 256 0

• 0 64

• 64 0

Answer explanation

Answer: c
Explanation: None.
output:

$ javac leftshift_operator.java $ java leftshift_operator 256 0

1. class Output

2. {

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

4. {

5. int arr[] = {1, 2, 3, 4, 5};

6. for ( int i = 0; i < arr.length - 2; ++i)

7. System.out.println(arr[i] + " ");

8. }

• 1 2 3 4 5

• 1 2 3 4

• 1 2 3

• 1 2

Answer explanation

arr.length() is 5, so the loop is executed for three times.
output:

$ javac Output.java $ java Output 1 2 3

Which exception is thrown when java is out of memory?

• MemoryError

• OutOfMemoryError

• MemoryOutOfBoundsException

• MemoryFullException

Answer explanation

The Xms flag has no default value, and Xmx typically has a default value of 256MB. A common use for these flags is when you encounter a java.lang.OutOfMemoryError.

Which of these are selection statements in Java?

• break

• continue

• for()

• if()

Answer explanation

Continue and break are jump statements, and for is a looping statement.