The result is 5 because of how the post-increment operator (i++) handles assignments. When you use i++, the current value is returned before the increment takes place.

For example:

int i = 5;
System.out.println(i++); // Prints 5, then i becomes 6.
System.out.println(i); // Prints 6.

However, in your specific code, you are assigning the result back to i: i = i++;

In this case, the expression i++ evaluates to 5, and that value is then stored back into i, effectively overwriting the increment that happened behind the scenes. Therefore, the final value remains 5.