将有父子关系的一维数组转换成树形结构(多维)数据

Question

已知原有数据 : var data=[ { id: 40, parentId: 31, note: "的萨达是" }, { id: 20, parentId: 11, note: "的萨达是" }, { id: 22, parentId: 20, note: "dsadas" }, { id: 12, parentId: null, note: "dsadasad萨达s" }, { id: 11, parentId: undefined, note: "dqwds" }, { id: 24, parentId: 22, note: "搜索" }, { id: 34, parentId: 22, note: "搜索" } ] 需要考虑的问题 : 不更改源数据 避免循环引用, 即 a的parentId为b, b的parentId为a 发挥你的大脑, 来个最优解

Answer 1

const toTree =
  (arr, pID) =>
    arr
      .filter(({ parentId }) => parentId == pID)
      .map(a => ({
        ...a,
        childers: toTree(arr.filter(({ parentId }) => parentId != pID), a.id)
      }))