js数组上移和下移

/**
 * UpDownFunction: 上移和下移
 * @params {*} arr: 数组
 * @params {*} index:需要处理的index
 * upData: 这是上移
 * downData： 这是下移
 */
export default class UpDownFunction {
  constructor(arr = [], index) {
    this.arr = arr
    this.index = index
  }

  swapItems(arr, index1, index2) {
    arr[index1] = arr.splice(index2, 1, arr[index1])[0]
    return arr
  }

  upData() {
    let newArr = []
    if (this.arr.length > 1 && this.index !== 0) {
      newArr = this.swapItems(this.arr, this.index, this.index - 1)
    }
    return newArr
  }
  downData() {
    let newArr = []
    if (this.arr.length > 1 && this.index !== (this.arr.length - 1)) {
      newArr = this.swapItems(this.arr, this.index, this.index + 1)
    }
    return newArr
  }
}

调用方式

const array = [
  {
    label:'测试1',
    id:1
  },
  {
    label:'测试2',
    id:2
  },
  {
    label:'测试3',
    id:3
  }
]
const upDataArray = []
const UpDownFunctions = new UpDownFunction(array, val.index)
this.upDataArray= UpDownFunctions.upData()