Justify the output?

Question

public class Program {
public static void main(String[] args) {
int x = 4;
int y = x++;
int w = x;
int z = y++;

System.out.println(y);
System.out.println(w);
System.out.println(z);
}
}

output:
5
5
4

why?

output should be:
4
5
4

Right?

Answer 1

Actually the original output is correct. You can read the expressions in this order:
int x = 4;
int y = x;
x=x+1;
int w = x;
int z = y;
y=y+1;
So, in the end you have y=5, w=5 and z=4.

Answer 2

You have to check again the meanings of prefix and postfix increment operators.
For example, y = x++ will perform assignment first then do the increment.