前端面试常问JavaScript继承的几种方法

　　js继承原型链实现继承function Parent() {     this.parent = ＂parent＂; }  Parent.prototype.getParent = function(){     return this.parent; }  function Son(){     this.son = ＂son＂; }  Son.prototype = new Parent(); //这句代码是实现继承的核心 Son.prototype.getSon = function(){     return this.son; }借用构造函数function Parent(){     this.child = [1];     this.getChild = function(){         return this.child;     } } function Son() {     Parent.call(this); } var son1 = new Son(); son1.child.push(2); son1.child //[1,2] var son2 = new Son(); son2.child.push(3); son2.child //[1,3]组合继承function Parent(){     this.child = [1] } Parent.prototype.getChild = function(){     return this.child; } function Son() {     Parent.call(this);     this.friend = ＂Jay Zangwill＂; } Son.prototype = new Parent(); Son.prototype.getFriend = function(){     return this.friend; } var son1 = new Son(); son1.child.push(2); son1.getChild(); //[1,2] var son2 = new Son(); son2.getChild(); //[1] son2.getFriend(); // Jay Zangwill寄生组合式继承
　　这个是最常问的，通常面试官会给一个场景让你手撕代码function createObj(obj){     function F(){};     F.prototype = obj;     return new F(); } function inherirPrototype(parent,son) {     var prototype = createObj(parent.prototype);     prototype.constructor = son;     son.prototype = prototype;    } function Parent(name){     this.name = name;     this.child = [1]; } Parent.prototype.getChild= function(){     return this.child; } function Son(name) {     Parent.call(this,name);     this.friend = [2]; }  inherirPrototype(Parent,Son);  Son.prototype.getFriend = function(){     return this.friend; } var son1 = new Son(＂Jay＂); son1.child.push(2); son1.getChild() //[1,2]; son2=new Son(＂Zangwill＂); son2.child.push(3); son2.getChild() //[1,3] son2.getFriend() //[2]