javascript prototype介绍的文章
JavaScript是基于对象的，任何元素都可以看成对象。然而，类型和对象是不同的。本文中，我们除了讨论类型和对象的一些特点之外，更重要的是研究如何写出好的并且利于重用的类型。毕竟，JavaScript这种流行的脚本语言如果能够进行良好的封装，并形成一个庞大的类型库，对于重用是非常有意义的。
网上对于prototype的文章很多，一直没明白核心的思想。最后写了很多例子代码后才明白：prototype只能用在类型上。
以下是一些关于类型和对象的例子，大家看完例子后可能更容易理解类型和对象之间的联系：
例子代码 说明
1 Object.prototype.Property = 1;
Object.prototype.Method = function ()
{
alert(1);
}
var obj = new Object();
alert(obj.Property);
obj.Method();
可以在类型上使用proptotype来为类型添加行为。这些行为只能在类型的实例上体现。
JS中允许的类型有Array, Boolean, Date, Enumerator, Error, Function, Number, Object, RegExp, String
2 var obj = new Object();
obj.prototype.Property = 1; //Error
//Error
obj.prototype.Method = function()
{
alert(1);
}
在实例上不能使用prototype，否则发生编译错误
3 Object.Property = 1;
Object.Method = function()
{
alert(1);
}
alert(Object.Property);
Object.Method();
可以为类型定义“静态”的属性和方法，直接在类型上调用即可
4 Object.Property = 1;
Object.Method = function()
{
alert(1);
}
var obj = new Object();
alert(obj.Property); //Error
obj.Method(); //Error
实例不能调用类型的静态属性或方法，否则发生对象未定义的错误。
5 function Aclass()
{
this.Property = 1;
this.Method = function()
{
alert(1);
}
}
var obj = new Aclass();
alert(obj.Property);
obj.Method();
这个例子演示了通常的在JavaScript中定义一个类型的方法
6 function Aclass()
{
this.Property = 1;
this.Method = function()
{
alert(1);
}
}
Aclass.prototype.Property2 = 2;
Aclass.prototype.Method2 = function
{
alert(2);
}
var obj = new Aclass();
alert(obj.Property2);
obj.Method2();
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