Java quiz 13: Working with while loop

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This program is a simple while loop. Working with while loop is needed regularly for every Java programmers.

Java quiz 13: Working with while loops

Level: Easy

What is written to the standard output as the result of executing the following code?

public class MyClass
{
  public static void main(String[] args)
  {
    int i = 1;
    int x = 1;
    while(i < 4)
    {
      x += i;
      i++;
    }
    System.out.print(x);
  }
}
  Author: Sar Maroof

Select the correct answer.


Answer explanation

  1. The initial value of i is 1. Each time the body of the loop is executed the value of i is incremented by one. The while statement returns true as long as the value of i is smaller than 5.
  2. By the first execution of the loop the value of i is 1, the statement of x += i; increments the value of x by i. The initial value of x is 1. So, x = x + i = 1 + 1 = 2.
  3. By the second execution of the loop the value of i is 2. x = x + i = 2 + 2 = 4.
  4.  By the third execution of the loop the value of i is 3. x = x + i = 4 + 3 = 7.
  5. By the fourth execution of the loop the value of i is 4. x = x + i = 7 + 4 = 11.
  6. By the fifth time the value of i is 5 and that is not smaller than 5. Therefore the loop is terminated and 11 is written to the standard output.

The correct answer is: d.

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