理想的继承范式——寄生组合式继承

 1 window.onload = function() {
 2     var person1 = new SubType("Gee", 20);
 3     var person2 = new SubType("Key", 21);
 4 
 5     person1.colors.push("yellow");
 6     alert("person1: " + person1.colors);    // red, blue, green, yellow
 7     alert("person2: " + person2.colors);    // red, blue, green
 8 
 9     person1.sayName();    // Gee
10     person2.sayAge();    // 21
11 };
12 
13 function object(o){
14     function F() {}
15     F.prototype = o;
16     return new F();
17 }
18 
19 /**
20  * 继承超类型的方法
21  * @param  {Object} subType   子类型
22  * @param  {Object} superType 超类型
23  * @return {null}
24  */
25 function inheritPrototype(subType, superType) {
26     var prototype = object(superType.prototype);    // 创建对象
27     prototype.constructor = subType;    // 增强对象
28     subType.prototype = prototype;    // 指定对象
29 }
30 
31 function SuperType(name) {
32     this.name = name;
33     this.colors = ["red", "blue", "green"];
34 }
35 
36 SuperType.prototype.sayName = function() {
37     alert(this.name);
38 };
39 
40 function SubType(name, age) {
41     SuperType.call(this, name);    // 继承属性，并传递参数，子类型将具有独立属性而非共享属性
42 
43     this.age = age;
44 }
45 
46 inheritPrototype(SubType, SuperType);
47 
48 SubType.prototype.sayAge = function () {
49     alert(this.age);
50 };