Function.prototype.call 和 Function.prototype.apply 的区别

时间:2022-03-23 19:52:59

 call和apply函数是function函数的基本属性,都可以用于更改函数对象和传递参数,是前端工程师常用的函数。具体使用方法请参考以下案列:

 例如:

   申明函数: var fn = function (msg, isalert) { if (isalert) alert(this + msg); };

   用法:

    call: fn.call(/*context,arg1,arg2,...*/);

    apply:fn.call(/*context,[arg1,arg2,...]*/);

   讲述:第一个参数(context)将成为 fn 函数的 this 对象,参数 arg1 对应fn函数的参数 msg,参数 arg2 对应fn函数的参数 isalert;

   注:apply函数的第二个参数是数组!!!

   模型:

<!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">
<head>
<title>call和apply函数</title>
<style type="text/css">
*{float:left;width:100%;margin-left:20px;}
*{max-height:100%;max-width:100%}
*,:after,:before{-webkit-box-sizing:border-box;-moz-box-sizing:border-box;box-sizing:border-box;-ms-box-sizing:border-box;-o-box-sizing:border-box}
html{font-size:10px;font-family:sans-serif;-ms-text-size-adjust:100%;-webkit-text-size-adjust:100%;-webkit-tap-highlight-color:transparent}
body{margin:0 auto;width:80%;background-color:#fff;color:#333;font-size:10pt;font-family:"Helvetica Neue Light","Helvetica Neue",Helvetica,Arial,"Lucida Grande",sans-serif;line-height:1.42857143}
div{margin:0;}
span{font-size:16px;font-weight:600;margin-top:10px;}
code{line-height:30px;padding:5px;margin:10px 20px;border:1px solid #fcc;}
.button
{
font-size: 16px;
font-weight: 300;
line-height: 32px; display: inline-block; width:auto;
height: 32px;
padding: 0 20px; -webkit-transition: .3s all;
-moz-transition: .3s all;
-ms-transition: .3s all;
-o-transition: .3s all;
transition: .3s all;
text-align: center;
text-decoration: none; color: #fff;
border: none;
border-radius: 4px; appearance: none;
-webkit-box-orient: vertical;
}
.button:hover,
.button:focus,
.button:active,
{
-webkit-box-shadow: inset 0 1px 3px rgba(0, 0, 0, .2);
-moz-box-shadow: inset 0 1px 3px rgba(0, 0, 0, .2);
box-shadow: inset 0 1px 3px rgba(0, 0, 0, .2);
text-shadow: 0 1px 0 rgba(255, 255, 255, .3); -ms-box-shadow: inset 0 1px 3px rgba(0, 0, 0, .2);
-o-box-shadow: inset 0 1px 3px rgba(0, 0, 0, .2);
}
.button:hover
{
text-decoration: none; color: #fff;
outline: none;
}
.button:focus
{
color: #fee;
}
.button:visited
{
color: #fff;
}
.button:active
{
text-decoration: none; color: #fff;
}
.button.gold
{
border-color: #feae1b;
background-color: #feae1b;
}
.button.gold:hover,
.button.gold:focus
{
border-color: #fec04e;
background-color: #fec04e;
}
.button.gold:active
{
color: #e59501;
border-color: #f3ab26;
background-color: #f3ab26;
}
</style>
<script type="text/javascript">
var fn = function (msg, isalert) {
if (isalert) alert(this + msg);
};
function call() {
fn.call("我是:", "工具包(cntooltik)", true);
}
function apply() {
fn.apply("我是:", ["工具包(cntooltik)", true]);
}
</script>
</head>
<body>
<span>申明函数:</span>
<div>
<code>
var fn = function (msg, isalert) {
if (isalert) alert(this + msg);
};
</code>
</div>
<span>函数调用:</span>
<div>
<code>
function call() {
fn.call("我是:", "工具包(cntooltik)", true);
}
</code>
</div>
<button class="button gold" onclick="javascript:call()">call函数测试</button>
<div>
<code>
function apply() {
fn.apply("我是:", ["工具包(cntooltik)", true]);
}
</code>
</div>
<button class="button gold" onclick="javascript:apply()">apply函数测试</button>
</body>
</html>