console 命令行工具 X clear
console
<!DOCTYOE HTML>
<html>
<head>
    <meta charset="utf-8"/>
    <title></title>
    <script src="js/jquery-1.12.4.min.js"></script>
    <script>
        $(function(){
           var colors=["red","blue","yellow","green"];
           $("li").each(function(index){
               $(this).css("backgroundcolor",colors[index]);
           })
        })
    </script>


</head>
<body>
    <ul>
        <li></li>
        <li></li>
        <li></li>
        <li></li>
    </ul>

</body>
</html>