javascript - js连续赋值的一个问题

Question

var a = {n: 1}
var b = a;
a.x = a = {n: 2}
console.log(a.x);//undefined
console.log(b.x)//{n:2}

哪位能帮忙解释一下

Answer 1

重复问题

http://segmentfault.com/q/1010000002637728