Object.create 以原对象为原型创建一个新对象

Object.create = function(o){
  var Fun = function(){};
  Fun.prototype = o;
  return new Fun();
}

var peo = {
  name:'liu',
  age : ,
}
var stu = Object.create(peo);
stu.sex = 'man';
console.log(stu)