Javascript order of execution of assignment expressions

Question

the results why x=5,y=4
x=y+(y=x)*0
this line
x=5+(4)*0
why not? x=4+(4)*0

var x=4; 
var y=5; 
x=y+(y=x)*0; 
console.log(x); 
console.log(y);

run on chrome console

Answer 1

Because y=x does not magically run before the rest of the line. JavaScript executes each bit in the expression as it comes; y comes first, and it is 5; then y = x comes, and it is 4.