How does a.x = a = {n: b} work in JavaScript?

Question

This is related to Javascript a=b=c statements.

I do understand that

foo = foo.x = {n: b}; // console.log(foo) => {n: b}

but

Answer 1

I got it.

var foo = {}; // now foo is a reference point to object {}
foo.x = foo = {n:1}; // first foo is refer to a new object {n:1}, then old foo referred object {} set a prop x

// try this to get what you want
var foo = foo1 = {};
foo.x = foo = {n:1};
console.log(foo, foo1) // here foo1 is what you want