一、原型链继承
function Person(){}; Person.prototype = { constructor: Person, name: "Oliver" }; function People(){}; People.prototype = new Person(); People.prototype.constructor = People; People.prototype.sayName = function(){ return this.name; }; var ins = new People(); console.log(ins.sayName());
二、借用构造函数（伪造对象，经典继承）
1、无参数
function SuperType(){ this.color = ["red","yellow","white"]; } function SubType(){ SuperType.call(this); } var instance1 = new SubType(); var instance2 = new SubType(); instance1.color.pop(); console.log(instance1.color); //["red", "yellow"] console.log(instance2.color); //["red", "yellow", "white"]
2、有参数
function SuperType(name){ this.name = name; this.number = [21,32,14,1]; } function SubType(name,age){ SuperType.call(this,name); this.age = age; } var instance1 = new SubType("Oliver",18); var instance2 = new SubType("Troy",24); instance2.number.pop(); console.log(instance1.name + instance1.age + instance1.number); //Oliver1821,32,14,1 console.log(instance2.name + instance2.age + instance2.number); //Troy2421,32,14
三、组合继承（伪经典继承）
1、无参数
function SuperType(){ this.color = ["red","yellow","white"]; } SuperType.prototype.sayColor = function(){ return this.color; }; function SubType(){ SuperType.call(this); this.number = 321; } SubType.prototype = new SuperType(); SubType.prototype.constructor = SubType; SubType.prototype.sayNumber = function(){ return this.number; }; var instance1 = new SubType(); var instance2 = new SubType(); instance2.color.pop(); console.log(instance1.color + instance1.number); //red,yellow,white321 console.log(instance2.color + instance2.number); //red,yellow321
2、有参数
function SuperType(name){ this.name = name; this.number = [32,1342,11,1]; } SuperType.prototype.sayName = function(){ return this.name; }; function SubType(name,age){ SuperType.call(this,name); this.age = age; } SubType.prototype = new SuperType(); SubType.prototype.constructor = SubType; SubType.prototype.sayAge = function(){ return this.age; }; var instance1 = new SubType("Oliver",18); var instance2 = new SubType("Troy",24); instance2.number.pop(); console.log(instance1.sayName() + instance1.sayAge() + instance1.number); //Oliver1832,1342,11,1 console.log(instance2.sayName() + instance2.sayAge() + instance2.number); //Troy2432,1342,11
三、寄生组合式继承（引用类型最理想的范式）
function inheritPrototype(subType,superType){ var prototype = Object(superType.prototype); prototype.constructor = subType; subType.prototype = prototype; } function SuperType(name){ this.name = name; this.number = [321,321,43]; } SuperType.prototype.sayName = function(){ return this.name; }; function SubType(name,age){ SuperType.call(this,name); this.age = age; } inheritPrototype(SubType,SuperType); SubType.prototype.sayAge = function(){ return this.age; }; var instance1 = new SubType("Oliver",18); var instance2 = new SubType("Troy",24); instance2.number.pop(); console.log(instance1.sayName() + instance1.sayAge() + instance1.number); //Oliver18321,321,43 console.log(instance2.sayName() + instance2.sayAge() + instance2.number); //Troy24321,321
或者可以把inheritPrototype 函数写成下面这样：
function inheritPrototype(SubType,SuperType){ SubType.prototype = new SuperType(); SubType.prototype.constructor = SubType; }
四、原型式继承（用于共享引用类型的值，与寄生式类似）
1、传统版（先定义object() 函数，再继承）
function object(o){ function F(){}; F.prototype = o; return new F(); } var SuperType = { name: "Oliver", number: [321,321,4532,1] }; var SubType1 = object(SuperType); var SubType2 = object(SuperType); SubType1.name = "Troy"; SubType1.number.pop(); SubType2.name = "Alice"; SubType2.number.pop(); console.log(SubType1.name + SubType2.name + SubType1.number + SubType2.number + SuperType.name + SuperType.number); //TroyAlice321,321321,321Oliver321,321
ECMAScript 5 版（直接用Object.create()，再继承）
var SuperType = { name: "Oliver", number: [321,321,4532,1] }; var SubType1 = Object.create(SuperType); //省略了定义object()函数 var SubType2 = Object.create(SuperType); SubType1.name = "Troy"; SubType1.number.pop(); SubType2.name = "Alice"; SubType2.number.pop(); console.log(SubType1.name + SubType2.name + SubType1.number + SubType2.number + SuperType.name + SuperType.number); //TroyAlice321,321321,321Oliver321,321
ECMAScript 5 简写版（定义Object.create()的第二个参数，再继承）