javascript面向对象的定义和初始化

1、混合的构造函数、原型方式，创建对象

<script type="text/javascript" language="javascript">
            /*
            混合的构造函数、原型方式，创建对象
            */            
            function Card(sID, myName) {
                this.id = sID;
                this.myName = myName;    
                this.balance = 0;
            }
            
            Card.prototype.saveMoney = function(money) {
                this.balance += money;
            }
            
            Card.prototype.showBalance = function() {
                alert(this.balance);
            }
            
            //使用对象
            var card1 = new Card(1000, "Jack");
            var card2 = new Card(2000, "Tom");
            
            card1.saveMoney(500);
            card2.saveMoney(300);
            
            card1.saveMoney(888);
            
            card1.showBalance();
            card2.showBalance();
   </script>        

2、动态原型方法

 

<script type="text/javascript" language="javascript">
            //动态原型方法
            //创建对象
            function Card(sId, myName) {
                this.id = sId;
                this.myName = myName;
                this.balance = 0;
                
                if(typeof(Card.inited) == "undefined") {
                    Card.prototype.saveMoney = function(money) {
                        this.balance += money;
                    }    
                    
                    Card.prototype.showBalance = function() {
                        alert(this.balance);
                    }
                    
                    Card.inited = true;
                }
            }
            
            //使用对象
            var card1 = new Card(1000, "Jack");
            var card2 = new Card(3000, "Tom");
            
            card1.saveMoney(333);
            card2.saveMoney(888);
            
            card1.showBalance();
            card2.showBalance();
   </script>