js实现继承的几种方式
1 构造函数
function SuperType() { this.colors = ["red","blue","green"]; } function SubType() { SuperType.call(this);//继承了SuperType }
2 原型链
function SuperType() { this.property = true; } SuperType.prototype.getSuperValue = function() { return this.property; } function subType() { this.property = false; } //继承了SuperType SubType.prototype = new SuperType(); SubType.prototype.getSubValue = function (){ return this.property; } var instance = new SubType(); console.log(instance.getSuperValue());//true
3 组合继承
function SuperType(name) { this.name = name; this.colors = ["red","blue","green"]; } SuperType.prototype.sayName = function() { console.log(this.name); } function SubType(name, age) { SuperType.call(this,name);//继承属性 this.age = age; } //继承方法 SubType.prototype = new SuperType(); Subtype.prototype.constructor = Subtype; Subtype.prototype.sayAge = function() { console.log(this.age); } var instance1 = new SubType("EvanChen",18); instance1.colors.push("black"); consol.log(instance1.colors);//"red","blue","green","black" instance1.sayName();//"EvanChen" instance1.sayAge();//18 var instance2 = new SubType("EvanChen666",20); console.log(instance2.colors);//"red","blue","green" instance2.sayName();//"EvanChen666" instance2.sayAge();//20
4 原型式继承
var person = { name:"EvanChen", friends:["Shelby","Court","Van"]; }; var anotherPerson = Object.create(person); anotherPerson.name = "Greg"; anotherPerson.friends.push("Rob"); var yetAnotherPerson = Object.create(person); yetAnotherPerson.name = "Linda"; yetAnotherPerson.friends.push("Barbie"); console.log(person.friends);//"Shelby","Court","Van","Rob","Barbie"
5 寄生式继承
function createAnother(original) { var clone = Object.create(original); clone.sayHi = function () { alert("hi"); }; return clone; } var person = { name:"EvanChen", friends:["Shelby","Court","Van"] }; var anotherPerson = createAnother(person); anotherPerson.sayHi();///"hi"
6 寄生组合式继承
function SuperType(name){ this.name = name; this.colors = ["red","blue","green"]; } SuperType.prototype.sayName = function (){ alert(this.name); }; function SubType(name,age){ SuperType.call(this,name); this.age = age; } inheritProperty(SubType,SuperType); SubType.prototype.sayAge = function() { alert(this.age); }