Javascript 自定义类型

1. 定义类型

function userobject(parameter) {

}

parameter 可省略，相当于C#中构造函数参数。

2. 实例化自定义类型

<script type="text/javascript">

function userobject(parameter){

}

//myobject is now an object of type userobject!

var myobject=new userobject("hi")

alert(myobject)

</script>

3. 添加属性

function userobject(parameter){

this.firstproperty=parameter

this.secondproperty="This is the second property"

}

//使用

<script>

var myobject=new userobject("hi there.")

//alerts "hi there."

alert(myobject.firstproperty)

//writes "This is the second property"

document.write(myobject.secondproperty)

</script>

 4.添加方法  （circle类）

//first method function

function computearea(){

var area=this.radius*this.radius*3.14

return area

}



//second method function

function computediameter(){

var diameter=this.radius*2

return diameter

}

关联到自定义类型：

<script type="text/javascript">

/*the below creates a new object, and gives it the two methods defined earlier*/

function circle(r){

//property that stores the radius 

this.radius=r

this.area=computearea

this.diameter=computediameter

}

</script>

使用自定义方法：

<script type="text/javascript">

var mycircle=new circle(20)

//alerts 1256

alert("area="+mycircle.area())

//alerts 400

alert("diameter="+mycircle.diameter())

</script>