標籤：nal height apply() www 1.0 public ansi xhtml 1.0 控制
普通函數中是否也有this關鍵字，this指向誰呢？
<script type="text/javascript"> function myfun(){ console.log(this); } myfun();</script>
控制函數內部的this指向：
函數都可以打點調用call()和apply()方法，可以幫我們制定函數內部的this指向，在函數調用過程使用這兩個方法。
var oDiv = document.getElementsByTagName(‘div‘);function fun(){ console.log(this);}//fun.call(oDiv);fun.apply(oDiv);
作用：
1、執行fun函數
2、在fun函數內部指定this的指向oDiv
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html;charset=UTF-8">
<title>Document</title>
<style type="text/css">
div{
width: 200px;
height: 200px;
background: red;
}
</style>
</head>
<body>
<div></div>
</body>
</html>
<script type="text/javascript">
/*function fun(){
console.log(this);
}
fun();*/
var oDiv = document.getElementsByTagName(‘div‘)[0];
/* function fun(){
console.log(this);
}
//fun.call(oDiv);
fun.apply(oDiv);*/
/*function sum(a,b){
this.style.backgroundColor = "pink";
}
sum.call(oDiv);
sum.apply(oDiv);*/
function sum(a,b){
this.style.backgroundColor = "pink";
console.log(a+b);
}
sum.call(oDiv,2,3);
sum.apply(oDiv,[3,5]);
</script>
call和apply 區別：
函數傳遞參數的文法不同。
sum.call(oDiv,參數1,參數2,參數3...);sum.apply(oDiv,[參數1,參數2,參數3...])
call和apply方法
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