//交換
alterItem:function(arr, index1, index2) {
arr[index1] = arr.splice(index2, 1, arr[index1])[0];
? ? return arr;
},
// 上移
? function(arr, index) {
??????? if(index == 0) {
??????????? return;
??????? }
??????? swapItems(arr, index, index - 1);
??? };
??? // 下移
function(arr, index) {
??????? if(index == arr.length -1) {
??????????? return;
??????? }
??????? swapItems(arr, index, index + 1);
??? };
來源https://www.cnblogs.com/yangyang03/p/7494403.html
