相思资源网 Design By www.200059.com

本文分享了js对象继承的N种模式,供大家参考。

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)

var SuperType = {
  name: "Oliver",
  number: [321,321,4532,1]
};

var SubType1 = Object.create(SuperType,{
  name: {
    value : "Troy"
  }
});
var SubType2 = Object.create(SuperType,{
  name: {
    value : "Alice"
  }
});

SubType1.number.pop();
SubType2.number.pop();

console.log(SubType1.name + SubType2.name + SubType1.number + SubType2.number + SuperType.name + SuperType.number); //TroyAlice321,321321,321Oliver321,321

寄生式继承(用于共享引用类型的值,与原型式类似)

function createAnother(original){
  var clone = Object(original);
  clone.sayHi = function(){
    return "Hi";
  };
  return clone;
}

var person = {
  name: "Oliver",
  number: [13,21,31,1]
};

var anotherPerson = createAnother(person);
anotherPerson.number.pop();

console.log(anotherPerson.sayHi() + anotherPerson.number); //Hi13,21,31
console.log(person.number); //13,21,31

以上就是本文的全部内容,希望对大家的学习有所帮助。

标签:
js,对象继承

相思资源网 Design By www.200059.com
广告合作:本站广告合作请联系QQ:858582 申请时备注:广告合作(否则不回)
免责声明:本站文章均来自网站采集或用户投稿,网站不提供任何软件下载或自行开发的软件! 如有用户或公司发现本站内容信息存在侵权行为,请邮件告知! 858582#qq.com
相思资源网 Design By www.200059.com

评论“理解js对象继承的N种模式”

暂无理解js对象继承的N种模式的评论...

《魔兽世界》大逃杀!60人新游玩模式《强袭风暴》3月21日上线

暴雪近日发布了《魔兽世界》10.2.6 更新内容,新游玩模式《强袭风暴》即将于3月21 日在亚服上线,届时玩家将前往阿拉希高地展开一场 60 人大逃杀对战。

艾泽拉斯的冒险者已经征服了艾泽拉斯的大地及遥远的彼岸。他们在对抗世界上最致命的敌人时展现出过人的手腕,并且成功阻止终结宇宙等级的威胁。当他们在为即将于《魔兽世界》资料片《地心之战》中来袭的萨拉塔斯势力做战斗准备时,他们还需要在熟悉的阿拉希高地面对一个全新的敌人──那就是彼此。在《巨龙崛起》10.2.6 更新的《强袭风暴》中,玩家将会进入一个全新的海盗主题大逃杀式限时活动,其中包含极高的风险和史诗级的奖励。

《强袭风暴》不是普通的战场,作为一个独立于主游戏之外的活动,玩家可以用大逃杀的风格来体验《魔兽世界》,不分职业、不分装备(除了你在赛局中捡到的),光是技巧和战略的强弱之分就能决定出谁才是能坚持到最后的赢家。本次活动将会开放单人和双人模式,玩家在加入海盗主题的预赛大厅区域前,可以从强袭风暴角色画面新增好友。游玩游戏将可以累计名望轨迹,《巨龙崛起》和《魔兽世界:巫妖王之怒 经典版》的玩家都可以获得奖励。