JavaScript 继承实例之一

<script type="text/javascript"> 
function Animal(name){ 
this.name=name; 
} 
Animal.prototype.sayName=function(){ 
alert("My name is:"+this.name); 
} 
Animal.prototype.sayHi=function(){ 
alert("Hi! from animal:"+this.name); 
}

function Tiger(name){ 
Animal.call(this, name);//call(obj,args...)它的第一个参数用作 this 的对象。其他参数都直接传递给函数自身。 
} 
Tiger.prototype=new Animal();//

Tiger.prototype.sayHi=function(){ 
alert("Hi! from tiger:"+this.name); 
}

var a1=new Animal("a1"); 
var a2=new Tiger("a2"); 
a1.sayName(); 
a1.sayHi(); 
alert(a1 instanceof Animal);//true 
alert(a1 instanceof Tiger);//false

a2.sayName(); 
a2.sayHi(); 
alert(a2 instanceof Animal);//true 
alert(a2 instanceof Tiger);//true 
</script>