Object.setPrototypeOf( obj, 父对象 prototype 子对象 )示例:
var obj1 = {a:1};
var obj2 = {b:2};
var b = Object.setPrototypeOf(obj1,obj2);
console.log(obj1.a, obj1.b);
console.log(obj2.a, obj2.b); 结果: obj1.a = 1 obj1.b = 2 obj2.a = undefined obj2.b = 2 注:父对象可读子对象属性,子对象不能读父对象属性