Java quiz 26: How unary operators work?

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The following example shows different kind of unary operators.

Java quiz 26: How unary operators work?

Level: Normal
What happens if the following code is compiled and run?

public class MyClass
{
  static int x = 8;
  
  public static void main(String[] args)
  {
    if(x == x--)
    {
      x -= 4;
    }
    else
    {
      x -= 3;
    }
    System.out.print(x++ + ++x + x++);
  }
}
Author: Sar Maroof

Select the correct answer.


Answer explanation

  1. The statement if(x == x–) returns true, because the value of x is decremented by one after the evaluation.
  2. The statement x -= 4; decrements the value of x by 4.
  3. The statement System.out.print(x++ + ++x + x++); prints the sum of x++, ++x and x++ to the standard output. x++ = 8-1-4 = 3, ++x = 3 +2 = 5, because the value of x is incremented by one a step before. The value of the last x++ remains 5. The statement writes (3 + 5 + 5) 13 to the standard output.

The correct answer is: b.

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3 Comments

Add a Comment
  1. The statement writes (4 + 6 + 6)

    1. this is wrong The statement writes (3 + 5 + 5), The trick is it evaluates the expression first so we miss the 6 and end up in adding 3, 5, 5. please correct me if i’m wrong

    2. Sorry sri, thanks for your comment. I have mixed two quizzes for different websites with the same idea, but different results. The end result is 3 + 5 + 5 = 13.

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