js学习总结----99乘法表

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
    <style>
        body,div,ul,li{
            margin:0;
            padding: 0;
            font-family: Arial;
            font-size:12px;
        }
        ul li{
            list-style:none;
        }
        #tab{
            position:absolute;
            top:50%;
            left:50%;
            padding:10px;
            margin-left:-460px;
            margin-top:-145px;
            width:900px;
            height:270px;
            border:1px solid red;
            border-radius:10px;
        }
        #tab li{
            height:30px;
            line-height: 30px;

        }
        #tab li span{
            width:100px;
            height:30px;
            text-align:center;
            display: inline-block;
        }
    </style>
</head>
<body>
    <div id='tab'>
        <ul>
            
        </ul>
    </div>
    <script type='text/javascript'>
        var oTab = document.getElementById('tab');
        var str = '';
        str+="<ul>"
            for(var i = 1;i<=9;i++){
                var val = "c1";
                switch(i%3){
                    case 0:
                        val = "c1";
                        break;
                    case 1:
                        val = "c2";
                        break;
                    default:
                        val = "c3";
                }
                str+="<li class='"+val+"'>";
                    for(var j = 1;j<=i;j++){
                        str+="<span>";
                            str+=""+j+"*"+i+" = "+(j*i)+""
                        str+="</span>"
                    }
                str+="</li>"
            }
        str+="</ul>"
        oTab.innerHTML = str;
        //字符串拼接的第一条黄金法则:单双不能同时用。必须间隔出现
        //如果一个字符串中需要增加一个变量,看最外面是""还是'',如果是"",那么直接的"+变量+"。如果是单引号'',那么直接的'"+变量+"'
    </script>
</body>
</html>

 

posted @ 2017-06-20 14:10  diasa  阅读(360)  评论(0编辑  收藏  举报