Java OCA OCP Practice Question 1437

Question

What will the following program print? 

public class Main {
   static boolean b;
   static int[] ia = new int[1];
   static char ch;
   static boolean[] ba = new boolean[1];

   public static void main(String args[]) throws Exception {
      boolean x = false;
      if (b) {/*  w  w w .  jav  a  2 s.  c  o  m*/
         x = (ch == ia[ch]);
      } else
         x = (ba[ch] = b);
      System.out.println(x + " " + ba[ch]);
   }
}

Select 1 option

  • A. true true
  • B. true false
  • C. false true
  • D. false false
  • E. It will not compile. 


Correct Option is  : D

Note

This question tests your knowledge on the default values of uninitialized primitives and object references.

booleans are initialized to false, numeric types to 0 and object references to null.

Elements of arrays are initialized to the default values of their types.

So, elements of a boolean array are initialized to false.

int, char, float to 0 and Objects to null.

In this case, b is false.

So the else part of if (b) is executed.

ch is a numeric type to its value is 0.

ba[0] = false assigns false to ba [0] and returns false which is assigned to x.

x and ba [0] are printed as false false.




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