javascript継承の組合せ継承(三)

 1 function Father(name) {
 2             this.name = name;            
 3         }
 4         Father.prototype.say = function () {
 5             return this.name;
 6         }
 7         function Son(name, age) {
 8             Father.call(this, name);
 9             this.age = age;
10         }
11         Son.prototype = new Father();
12         /*  constructor     , son     father     ,
13           son    constructor   father   , father      constructor  father.
14           Son.prototype.constructor     son.
15                           
16         */
17         Son.prototype.constructor = Son;        
18         var s = new Son("   ", 23);
19         alert(s.say()); //   
20         alert(s.age);//23