<script>
//创建数组
var arr = ['*', '##', "***", "&&", "****", "##*"];
arr[7] = "**";
//显示数组长度
alert(arr.length)
var a = [0, 7, 2, 4]
for (var i = 0; i < a.length; i++) {
var b = a[i]
document.write(arr[b] + '<br>')
}
</script>//创建数组
var arr = ['*','##',"***","&&","****","##*"];
arr[7] = "**";
//显示数组长度
alert(arr.length);
//将数组内容输出，完成达到的效果。
for(i=0;i<arr.length;i++){
document.write(arr[i]+"<br/>");
}