Javascript 自訂類型

1. 定義類型

function userobject(parameter) {}parameter 可省略，相當於C#中建構函式參數。

2. 執行個體化自訂類型

<script type="text/javascript">function userobject(parameter){}//myobject is now an object of type userobject!var myobject=new userobject("hi")

alert(myobject)</script>

3. 添加屬性

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類）

//first method functionfunction computearea(){var area=this.radius*this.radius*3.14return area}//second method functionfunction computediameter(){var diameter=this.radius*2return diameter}

關聯到自訂類型：

<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=rthis.area=computeareathis.diameter=computediameter}</script>

使用自訂方法：

<script type="text/javascript">var mycircle=new circle(20)//alerts 1256alert("area="+mycircle.area())//alerts 400alert("diameter="+mycircle.diameter())</script>