JavaScript中的静态成员

 1 var Gadget = function(price) {
 2     this.price = price;
 3 }
 4 Gadget.isShiny = function(){
 5     var msg = ‘you bet‘;//公有静态
 6     if(this instanceof Gadget){//实例调用时
 7         msg += ‘, it costs ‘ + this.price + ‘!‘;
 8     }
 9     return msg;
10 }
11 Gadget.prototype.isShiny = function(){
12     return Gadget.isShiny.call(this)
13 }
14 
15 console.log(Gadget.isShiny());//you bet  此为静态调用
16 var a = new Gadget(23);
17 console.log(a.isShiny());//you bet, it costs 23!   此为实例调用

 1 var Person;
 2 (function(){
 3     var id = 0;//私有
 4     Person = function(){
 5         id ++;
 6         this.id = id;
 7     }
 8     Person.prototype.getId = function(){
 9         console.log(this.id);
10     }
11     Person.prototype.getLastId = function(){
12         console.log(id);
13     }
14 
15 })();
16 
17 
18 var p1 = new Person();
19 p1.getLastId();//1
20 p1.getId();//1
21 
22 var p2 = new Person();
23 p2.getLastId();//2
24 p2.getId()//2
25 
26 var p3 = new Person();
27 p3.getLastId();//3
28 p3.getId();//3
29 
30 
31 p1.getId();//1
32 p2.getId();//2
33 p3.getId();//3