slice切割数组arr=[[0,1],[2,3]]

for (var i = 0; i < 10; i++) {
                arr.push(i)
            }
            function arrSlice(arr, num) {
                var arr1 = [];
                for (var i = 0; i < arr.length / num; i++) {
                    arr1.push(arr.slice(num * i, num * i + num))
                }
                return arr1;
            }

var arr3=[];

arr3 = arrSlice(arr, 2) //将数组弄成下标分组