Use Javascript to move elements up and down in an array

This article mainly introduces you to the relevant information about Javascript's implementation of moving elements in an array up and down. The article introduces it in detail through sample codes, which has certain reference and learning value for everyone. Friends who need it can take a look below. Bar.

Preface

We exchange arrays to move elements up and down. We will use this effect in tables or previous sorting algorithms, as follows Let’s look at an example of moving up and down swapping array elements in JavaScript

When writing a project, we need to implement an example of moving up and down array records. It's not troublesome to write, it's nothing more than exchanging array elements. The final implementation code is as follows, the more important thing is that function.

Sample code:

// 交换数组元素
  var swapItems = function(arr, index1, index2) {
    arr[index1] = arr.splice(index2, 1, arr[index1])[0];
    return arr;
  };
 
  // 上移
  $scope.upRecord = function(arr, $index) {
    if($index == 0) {
      return;
    }
    swapItems(arr, $index, $index - 1);
  };
 
  // 下移
  $scope.downRecord = function(arr, $index) {
    if($index == arr.length -1) {
      return;
    }
    swapItems(arr, $index, $index + 1);
  };

Using that method reasonably can achieve top and bottom implementations.

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