The assignment to variable x has no effect

Question

public class A{
int x;
public static void main(String args[])
A a = new A();
a.someMethod();
someMethod()
x=x++;
System.out.println("Value of x...."+x);
I am getting warning that The assignment to variable x has no effect and the output i get is 10;
On the otherhand if i use x=(x=x+1) then i get output as 11 without any warning.
I think i am doing something wrong, but just cant figure out.
Someone please help

Answer 1

From a bytecode perspective, it looks like this:
int x = 0;   // iconst_0:    variables { }, stack {0}
            // istore_1:    variables {0}, stack { }
x = x++;    // iload_1:     variables {0}, stack {0}
            // iinc 1, 1:   variables {1}, stack {0}
            // istore_1:    variables {0}, stack { }