How does the postfix y++ inside an equation (statement) work?

Question

In JavaScript: What is the output of this code below and please explain it... How is this postfix working?

var x=2;
var y=1;
y=x++; // y equals 2 or 3??
var z=x*y;
document.write(z);

Answer 1

The output should be 6.

The statement "y=x++" makes y=2 and x=3. This is because y was assigned the "original" value of x, which was 2 and then x was incremented (x++).

Note that "y=x++" is totally different from "y=++x". If instead, "y=++x" was used in this code, y would then be assigned the value of x++, which is 3 and x would be incremented to 3 also. Which would give the output of 9 :]

Answer 2

thank you very much!