关于回调函数为什么不能直接将执行的函数作为参数而要嵌套一个匿名函数？
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
<style type="text/css">
ul,li{
list-style: none;
}
ul li{
width: 200px;
height: 100px;
background: red;
margin-bottom: 20px;
border: 4px solid #000;
font-size: 8px;
filter: alpha(opacity:30);
opacity: 0.3;
}
</style>
<script type="text/javascript">
window.onload=function(){
var li1=document.getElementById("li1");
li1.timer=null;
li1.onmouseover=function(){
startMove(li1,400,'width',startMove(li1,200,'height'));
}
li1.onmouseout=function(){
startMove(li1,200,'width',startMove(li1,100,'height'));
}
}
function startMove(obj,iTarget,attr,fn){
clearInterval(obj.timer);
obj.timer=setInterval(function(){
var icur=0;
if(attr=='opacity'){
icur=Math.round(parseFloat(getStyle(obj,attr))*100);
}
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var speed=(iTarget-icur)/10;
speed=speed>0?Math.ceil(speed):Math.floor(speed);
if(icur==iTarget)
{clearInterval(obj.timer);
if(fn) {fn();}
}
else{
if (attr=='opacity') {obj.style[attr]=(icur+speed)/100;}
else {obj.style[attr]=icur+speed+'px';} }
},20);
}
function getStyle(obj,attr){
if(obj.currentStyle){
return obj.currentStyle[attr];
}
else{
return getComputedStyle(obj,false)[attr];
}
}
</script>
</head>
<body>
<ul>
<li id="li1"></li>
</ul>
</body>
</html>求解关于回调函数为什么不能直接将执行的函数作为参数而要嵌套一个匿名函数？
