Assignment and increment

Question

Explain Why following code alerts 5 and not 6. I know it applies assignment first and increment next.
https://code.sololearn.com/WfFESf1hUsox/?ref=app

Answer 1

https://stackoverflow.com/questions/7911776/what-is-x-after-x-x

Answer 2

https://www.codecademy.com/en/forum_questions/514995a07272221a5b001f32
Here it is nicely explained

Answer 3

var x=5;
x= x++;
//x++ does not increment because the value here is: 5

Answer 4

In the post he said x++ evaluates to x and hence old value is assigned to x. But after assignment increment operator should execute and increase the value of x by 1 right?