Quiz Discussion

Which of these statements are incorrect?

• 1]

  Assignment operators are more efficiently implemented by Java run-time system than their equivalent long forms

• 2]

  Assignment operators run faster than their equivalent long forms

• 3]

  Assignment operators can be used only with numeric and character data type

• 4]

  None of the mentioned

Which of these statements are incorrect?

• 1]

  The left shift operator, <<, shifts all of the bits in a value to the left specified number of times

• 2]

  The right shift operator, >>, shifts all of the bits in a value to the right specified number of time

• 3]

  The left shift operator can be used as an alternative to multiplying by 2

• 4]

  The right shift operator automatically fills the higher order bits with 0

What will be the output of the following Java code?

    class bool_operator 
    {
        public static void main(String args[]) 
        {    
             boolean a = true;
             boolean b = !true;
             boolean c = a | b;
 	     boolean d = a & b;
             boolean e = d ? b : c;
             System.out.println(d + " " + e);
        } 
    }

• 1]

  false false

• 2]

  true ture

• 3]

  true false

• 4]

  false true

What should be expression1 evaluate to in using ternary operator as in this line?

 expression1 ?  expression2  :  expression3

• 1]

  Integer

• 2]

  Floating – point numbers

• 3]

  Boolean

• 4]

  None of the mentioned

What is the order of precedence (highest to lowest) of following operators?

    1. &    
    2. ^
    3. ?:

• 1]

  1 -> 2 -> 3

• 2]

  2 -> 1 -> 3

• 3]

  3 -> 2 -> 1

• 4]

  2 -> 3 -> 1

What is the output of relational operators?

• 1]

  Integer

• 2]

  Boolean

• 3]

  Characters

• 4]

  Double

What will be the output of the following Java program?

    class leftshift_operator 
    {
        public static void main(String args[]) 
        {        
             byte x = 64;
             int i;
             byte y; 
             i = x << 2;
             y = (byte) (x << 2)
             System.out.print(i + " " + y);
        } 
    }

• 1]

  0 64

• 2]

  64 0

• 3]

  0 256

• 4]

  256 0

What will be the output of the following Java code?

    class ternary_operator 
    {
        public static void main(String args[]) 
        {        
             int x = 3;
             int y = ~ x;
             int z;
             z = x > y ? x : y;
             System.out.print(z);
        } 
    }

• 1]

  0

• 2]

  1

• 3]

  3

• 4]

  -4

What will be the output of the following Java code?

class Output 
{
        public static void main(String args[]) 
        {    
             int x=y=z=20;
 
        } 
}

• 1]

  compile and runs fine

• 2]

  20

• 3]

  run time error

• 4]

  compile time error

Which of these lines of Java code will give better performance?

   1. a | 4 + c >> b & 7; 
   2. (a | ((( 4 * c ) >> b ) & 7 ))

• 1]

  1 will give better performance as it has no parentheses

• 2]

  2 will give better performance as it has parentheses

• 3]

  Both 1 & 2 will give equal performance

• 4]

  Dependent on the computer system