java - 如何工作：x = x++？

Question

Java 代码如下：

    int x = 10;
    while (x != 15){
       x = x++;
       System.out.println("Value X " + x);
    }

执行：无限循环？为什么 ？

Answer 1

Because x will never change and always will be 10. Read JLS.

Answer 2

I may be wrong but x++ incrementes x after reading it so x = x++ means x = x. You should use x = ++x instead.

See this question

Answer 3

Becouse you assign the old value of x to x befor you increase the value! Try this:

int x = 10;
while (x != 15){
   x++;
}

or

int x = 10;
while (x != 15){
   x = ++x;
}

Answer 4

x++; increments the value of x then returns the old value of x.

THEN x = (that number) executes, meaning the mutation x++ did of x is undone.

Answer 5

该行x = x++;应该是x++;

Answer 6

Because x = x++ will assign the result of the operation x++ to x. What you want is only x++;, which increments the value of x by one.