js对象引用赋值后

 a={f:1}
b={}
b.a=a
console.log(b.a)
a.b=2
console.log(b.a)

 a={f:1}
b={}
b.a=a
console.log(b.a)
a={b:1}
console.log(b.a)

对象引用赋值后，如果将对象置空，相互间是不受影响的，如下：

var arr = {"a":"1","b":"2"};
var arr1 = arr;
arr = {};
arr["a"] = 2;
console.log(arr1);
console.log(arr);

输出结果：{"a":"1","b":"2"}，{"a":2}