二十一天

    var arr = [  
            ["周更生","男",30,true,"大专",5000,500,,"山东省"],
            ["刘晓庆","女",26,false,"研究生",8000,1500,"北京科技大学","山西省"],
            ["习近","男",38,true,"大专",1000,250,"清华大学","陕西省"],
            ["克强","女",34,true,"高中",11000,30,"河北大学","江苏省"],
          ];
    var arr_length=arr.length;
    //定义一个tablbe
    var str="<table width=‘600‘ border=‘1px‘ align=‘center‘ style=‘border-collapse:collapse‘;>";
        str+="<caption><h2>学生信息表</h2></caption>";
        for(var i=0;i<arr_length;i++)
        {
            str+="<tr";
              if(i%2==0){
                str+=" bgColor=‘red‘";
            }
            str+=">"

            //分部单行加颜色
            // if(i%2==0){
            //     str+="<tr bgColor=‘red‘>";
            // }else{
            //     str+="<tr>";
            // }

            // str+="<tr";
            // if(i%2==0){
            //     str+=" bgColor=‘red‘";
            // }
            // str+=">"
            
            for(var j=0;j<arr[i].length;j++){
                str+="<td>"+arr[i][j]+"</td>";
            }
            str+="</tr>";
        }

        str+="</table>";
        document.write(str);