二维数组和三维数组

<script>        //二维数组        var menuType = ["凉菜","热菜","主食"];        var menu = [            ["拍黄瓜","凉拌豆腐","水果沙拉"],            ["宫保鸡丁","红烧肉","木须肉"],            ["水饺","馒头","米饭"],        ]        for(var row=0;row<menu.length;row++){            document.write(menuType[row]+"<br>");            for(var col=0;col<menu[0].length;col++){                document.write(menu[row][col]+" ");            }            document.write("<br>");        }        //多维数组        var threeDimensionalArray =[            [[1,2,3,4],[5,6,7,8]],            [[1,2,3,4],[5,6,7,8]],            [[1,2,99,4],[5,6,7,8]],        ];       // document.write("<br>"+threeDimensionalArray[2][0][2]);        for(var row=0;row<threeDimensionalArray.length;row++) {            for(var col=0;col<threeDimensionalArray[0].length;col++){                for(var elem=0;elem<threeDimensionalArray[0][0].length;elem++){                    document.write(threeDimensionalArray[row][col][elem]);                    document.write(",");                }                document.write(" ");            }            document.write("<br>");        }    </script>