1.数组的创建

1-1一维数组

<script>
        var arr=[1,2,3,4];
        var a=["html","123","name:ming"]
        console.log(a)
</script>

1-2二维数组

<script>
        var arr=[[1,2],[3,4]];
        console.log(arr[0][1]);//1
        console.log(arr[1][0]);//3
 </script>