Why the value plus plus at last is 100?

when i use ++ operator in javascript, why I get the value at last is 100 not 101?
I want to know the detail of the ++ operator in javascript?

let value = 100;
value = value++;
console.log(value); // 100 why the value is 100 at last

>Solution :

Because when you have the assignment operator, the right-hand operand is evaluated first, then that value is assigned to the receiver on the left.¹

So here’s what happens in value = value++:

1. Read the value of value (100) and set it aside (since we’ll need it in a minute).
2. Increase the value of value by one (making it 101).
3. Take the value from #1 (100) as the result value of the right-hand operand.
4. Store that value in value.

¹ In specification terms it’s slightly more complicated than that, but the details aren’t important here.