When this line executes: i = i++ + m(i); the operands are evaluated from left to right. First, the left hand operand is evaluated: i = 0, so the equation becomes i = 0 + m(i); However, as we're using a post-increment operator, we now increment i to 1. Now we evaluate the next operand, m(i), by sending 1 to that method. That results in the number 1 being printed, followed by a comma. Also, that method returns a 0, so our original formula evaluates to: i = 0 + 0; Therefore, the answer is: 1,0 I hope that helps, Corey