对于数据属性，可以取得：configurable,enumberable,writable和value；

对于访问器属性，可以取得：configurable,enumberable,get和set；

继承机制实现

对象冒充

function Father(name) {
    this.name = name ;
    this.getName = function () {
        return this.name;
    }
 }
function Son(name,age) {
    this._newMethod = Father;
    this._newMethod(name);
    delete  this._newMethod;

    this.age = age;
    this.getAge = function () {
        return this.age;
    }
 }
var father = new Father("Tom");
var son = new Son("Jack",18);
console.log(father.getName());//Tom
console.log(son.getName());//Jack//继承父类getName()方法
console.log(son.getAge());//18
 

多继承（利用对象冒充可以实现多继承）

function FatherA(name) {
    this.name = name ;
    this.getName = function () {
        return this.name;
    }
 }
function FatherB(job) {
    this.job = job;
    this.getJob = function () {
        return this.job;
    }
 }
function Son(name,job,age) {
    this._newMethod = FatherA;
    this._newMethod(name);
    delete  this._newMethod;
    this._newMethod = FatherB;
    this._newMethod(job);
    delete  this._newMethod;

    this.age = age;
    this.getAge = function () {
        return this.age;
    }
 }
var fatherA = new FatherA("Tom");
var fatherB = new FatherB("Engineer");
var son = new Son("Jack","Programmer",18);
console.log(fatherA.getName());//Tom
console.log(fatherB.getJob());//Engineer
console.log(son.getName());//Jack//继承父类FatherA的getName()方法
console.log(son.getJob());//Programmer//继承父类FatherB的getJob()方法
console.log(son.getAge());//18
 

call()方法

function Father(name) {
    this.name = name ;
    this.getName = function () {
        return this.name;
    }
 }
function Son(name,job,age) {
    Father.call(this,name);

    this.age = age;
    this.getAge = function () {
        return this.age;
    }
 }
var father = new Father("Tom");
var son = new Son("Jack","Programmer",18);
console.log(father.getName());//Tom
console.log(son.getName());//Jack//继承父类getName()方法
console.log(son.getAge());//18
 

多继承（利用call()方法实现多继承）