• ( 1 ) Which of these operators can skip evaluating right hand operand?

    • 1) !
    • 2) |
    • 3) &
    • 4) &&
    • Discussion in forum
      Answer : 4) &&
      Solution : Operator short circuit and, &&, and short circuit or, ||, skip evaluating right hand operand when output can be determined by left operand alone.








      discussion


      Answer : 4) &&

    • ( 2 ) What will be the output after compiling and running following code?
      public class Test{
      public static void main(String... args){
      int x =5;
      x *= 3 + 7;
      System.out.println(x);
      }
      }

    • 1) 22
    • 2) 50
    • 3) 10
    • 4) Compilation fails with an error at line 4
    • Discussion in forum
      Answer : 2) 50
      Solution :








      discussion


      Answer : 2) 50

    • ( 3 ) What is the output of the following program?
      lass Operators1
      {
      public static void main(String[] args)
      {
      int a=3, b=6;
      System.out.println((~a&b)|(a&~b));
      }
      }

    • 1) 5
    • 2) 9
    • 3) 6
    • 4) None of these
    • Discussion in forum
      Answer : 1) 5
      Solution : a = 00000011
      ~a = 11111100 = 00000100 (2's complement)= -4
      b = 00000110
      ----------------
      ~a&b= 00000100
      a = 00000011
      ~b = 11111001 = 00000111 (2's complement)= -7
      ----------------
      a&~b= 00000001
      (~a&b)|(a&~b)
      00000100
      OR 00000001
      -----------
      00000101 = 5








      discussion


      Answer : 1) 5

    • ( 4 ) 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
    • Discussion in forum
      Answer : 4) 3 & 2
      Solution : Operator ++ increases value of variable by 1. x = x + 1 can also be written in shorthand form as x += 1. Also x =+ 1 will set the value of x to 1.








      discussion


      Answer : 4) 3 & 2

    • ( 5 ) What is the output of the following program?
      class Operators1
      {
      public static void main(String[] args)
      {
      int i=5,j;
      j=i++ + i + ++i;
      System.out.println("i="+i);
      System.out.println("j="+j);
      }
      }

    • 1) 1=7
      j=17
    • 2) i=6 j=16
    • 3) i=7 j=21
    • 4) i=7 j=18
    • Discussion in forum
      Answer : 4) i=7 j=18
      Solution : Since, i is incremented twice in the statement, i =7
      j=18= 5 + 6 + 7








      discussion


      Answer : 4) i=7 j=18

    • ( 6 ) class Test
      {
      static int s;
      public static void main(String [] args)
      {
      Test p = new Test();
      p.start();
      System.out.println(s);
      }
      void start()
      {
      int x = 7;
      twice(x);
      System.out.print(x + " ");
      }
      void twice(int x)
      {
      x = x*2;
      s = x;
      }
      }

    • 1) 7 7
    • 2) 7 14
    • 3) 14 0
    • 4) 14 14
    • Discussion in forum
      Answer : 2) 7 14
      Solution : The int x in the twice() method is not the same int x as in the start() method. Start()'s x is not affected by the twice() method. The instance variable s is updated by twice()'s x, which is 14.








      discussion


      Answer : 2) 7 14

    • ( 7 ) What is the value stored in x in following lines of code?
      int x, y, z;
      x = 0;
      y = 1;
      x = y = z = 8;

    • 1) 0
    • 2) 1
    • 3) 9
    • 4) 7
    • Discussion in forum
      Answer : 3) 9
      Solution :








      discussion


      Answer : 3) 9

    • ( 9 ) What is the output of this 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) 64 0
    • 2) 0 64
    • 3) 0 256
    • 4) 256 0
    • Discussion in forum
      Answer : 4) 256 0
      Solution :








      discussion


      Answer : 4) 256 0

    • ( 10 ) public class Test{
      public static void main(String args[]){
      System.out.print(""=="");
      System.out.print(" ");
      System.out.print("A"=="A");
      System.out.print(" ");
      System.out.print("a==A");
      }
      }

    • 1) "==" A"=="A a==A
    • 2) true true false
    • 3) true true a==A
    • 4) Compilation Fails
    • Discussion in forum
      Answer : 3) true true a==A
      Solution :








      discussion


      Answer : 3) true true a==A





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