Quiz Discussion

With x = 0, which of the following are legal lines of Java code for changing the value of x to 1?

   1. x++;
   2. x = x + 1;
   3. x += 1;
   4. x =+ 1;

• 1]

  1, 2 & 3

• 2]

  1 & 4

• 3]

  1, 2, 3 & 4

• 4]

  3 & 2

Which of these operators can skip evaluating right hand operand?

• 1]

  !

• 2]

  |

• 3]

  &

• 4]

  &&

 What is the value stored in x in the following lines of Java code?

   int x, y, z;
    x = 0;
    y = 1;
    x = y = z = 8;

• 1]

  0

• 2]

  1

• 3]

  9

• 4]

  8

What will be the output of the following Java program?

    class rightshift_operator 
    {
        public static void main(String args[]) 
        {    
             int x; 
             x = 10;
             x = x >> 1;
             System.out.println(x);
        } 
    }

• 1]

  10

• 2]

  5

• 3]

  2

• 4]

  20

What will be the output of the following Java program?

    class Output 
    {
        public static void main(String args[]) 
        {    
             int a = 1;
             int b = 2;
             int c;
             int d;
             c = ++b;
             d = a++;
             c++;
             b++;
             ++a;
             System.out.println(a + " " + b + " " + c);
        } 
    }

• 1]

  3 2 4

• 2]

  3 2 3

• 3]

  2 3 4

• 4]

  3 4 4

Which of these statements is correct?

• 1]

  true and false are numeric values 1 and 0

• 2]

  true and false are numeric values 0 and 1

• 3]

  true is any non zero value and false is 0

• 4]

  true and false are non numeric values

What will be the output of the following Java code?

    class Output 
    {
        public static void main(String args[]) 
        {    
             int x , y = 1;
             x = 10;
             if (x != 10 && x / 0 == 0)
                 System.out.println(y);
             else
                 System.out.println(++y);
        } 
    }

• 1]

  1

• 2]

  2

• 3]

  Runtime error owing to division by zero in if condition

• 4]

  Unpredictable behavior of program

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

Which right shift operator preserves the sign of the value?

• 1]

  <<

• 2]

  >>

• 3]

  <<=

• 4]

  >>=

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