<!DOCTYPE?html>
<html>
<head>
????<meta?charset="UTF-8">
????<title>構造函數</title>
????<script>
????????function?Rect(w,h)
????????{
????????????this.width=w;
????????????this.height=h;
????????????this.area=function()
????????????{
????????????????return?this.width*this.height;
????????????}
????????}
????????var?r=new?Rect(5,10);
????????alert(r.area)
????</script>
</head>
<body>
</body>
</html>請問我在視頻上看的這樣正確的應該是求出r.area的值也就是50. 但我為什么彈出的是function()
????????????{
????????????????return?this.width*this.height;
????????????}這個函數本身啊？還有個問題就是，在上面的構造函數中 ?定義完this.width=w; this.height=h;之后定義this.area的時候為什么不能直接定義this.area=this.width*this.height啊 ?視頻上非要套個函數也就是這樣this.area=function()
????????????{
????????????????return?this.width*this.height;
????????????}
新手構造函數初級問題
Ni14
2016-12-09 16:31:22
