数组转为tree

转载

冷月凤清7 2022-04-11 15:03:13

最顶层的parent 为 -1 ，其余的 parent都是为上一层节点的id

let arr = [
      { id: 0, name: '1', parent: -1, childNode: [] },
      { id: 1, name: '1', parent: 0, childNode: [] },
      { id: 99, name: '1-1', parent: 1, childNode: [] },
      { id: 111, name: '1-1-1', parent: 99, childNode: [] },
      { id: 66, name: '1-1-2', parent: 99, childNode: [] },
      { id: 1121, name: '1-1-2-1', parent: 112, childNode: [] },
      { id: 12, name: '1-2', parent: 1, childNode: [] },
      { id: 2, name: '2', parent: 0, childNode: [] },
      { id: 21, name: '2-1', parent: 2, childNode: [] },
      { id: 22, name: '2-2', parent: 2, childNode: [] },
      { id: 221, name: '2-2-1', parent: 22, childNode: [] },
      { id: 3, name: '3', parent: 0, childNode: [] },
      { id: 31, name: '3-1', parent: 3, childNode: [] },
      { id: 32, name: '3-2', parent: 3, childNode: [] }
    ]

    function arrToTree(arr, parentId) {
       // 判断是否是顶层节点，如果是就返回。不是的话就判断是不是自己要找的子节点
      const filterArr = arr.filter(item => {
        return parentId === undefined ? item.parent === -1 : item.parent === parentId
      })
       
      // 进行递归调用把子节点加到父节点的 childNode里面去
      filterArr.map(item => {
        item.childNode = arrToTree(arr, item.id)
        return item
      })
       
      return filterArr
    }
    
    arrToTree(arr)