this的指向:
1 //this 指的是调用 当前方法 (函数) 的那个对象2 3 function fn1(){4 this; 5 }6 7 //fn1(); this => window8 //obj.onclick=fn1; this=>obj9 //obj.onclick=function(){ this; } this=>window;
this的应用:
1 <!DOCTYPE html> 2 <html> 3 <head> 4 <meta charset="utf-8" /> 5 <title></title> 6 <style type="text/CSS"> 7 *{margin: 0;padding: 0;} 8 ul,li{list-style: none;} 9 li { width:100px; height:150px; float:left; margin-right:30px; background:#f1f1f1; position:relative; z-index:1; }10 div { width:80px; height:200px; background:red; position:absolute; top:75px; left:10px; display:none; }11 </style>12 <script type="text/javascript">13 window.onload=function(){14 var oUl=document.getElementById("ul1");15 var aLi=oUl.getElementsByTagName("li");16 17 for(var i=0;i<aLi.length;i++){18 aLi[i].onmouSEOver=function(){19 this.getElementsByTagName("div")[0].style.display="block";20 };21 aLi[i].onmouseout=function(){22 this.getElementsByTagName("div")[0].style.display="none";23 };24 };25 };26 </script>27 </head>28 <body>29 <ul id="ul1">30 <li><div></div></li>31 <li><div></div></li>32 <li><div></div></li>33 <li><div></div></li>34 </ul>35 </body>36 </html>
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