JavaScript对象要点

JavaScript原型使用要点

组合使用构造函数模式和原型模式

代码

//组合使用构造函数模式和原型模式//构造函数function Person(name, age, job) {  //实例属性  this.name = name;  this.age = age;  this.job = job;  this.friends = ["Shelby", "Court"];}//原型Person.prototype = {  constructor: Person,//设置constructor值  //原型方法  sayName: function() {    console.log(this.name);  }}//测试代码var person1 = new Person("Nicholas", 29, "Software Engineer");var person2 = new Person("Greg", 27, "Doctor");person1.friends.push("Van");console.log(person1.friends);console.log(person2.friends);console.log(person1.friends === person2.friends);console.log(person1.sayName === person2.sayName);

结果

[ ‘Shelby’, ‘Court’, ‘Van’ ]

[ ‘Shelby’, ‘Court’ ]

false

true

寄生组合式继承

代码

//寄生组合式继承function inheritPrototype(subType, superType) {  var prototype = Object(superType.prototype); //创建对象  prototype.constructor = subType; //增强对象  subType.prototype = prototype; //指定对象}function SuperType(name) {  this.name = name;  this.color = ["red", "blue", "green"];}SuperType.prototype.sayName = function() {  console.log(this.name);};function SubType(name, age) {  SuperType.call(this, name);//在this作用域下调用SuperType构造函数  this.age = age;}inheritPrototype(SubType, SuperType);SubType.prototype.sayAge = function() {  console.log(this.age);}//测试代码var sub = new SubType("Damian", 20);sub.sayName();sub.sayAge();console.log(sub.color);

结果

Damian

20

[ ‘red’, ‘blue’, ‘green’ ]