数组元素可以以混乱的顺序排列

let array = [ { id: 1, data: 'something', parent_id: null, children: [] }, { id: 2, data: 'something', parent_id: 1, children: [] }, { id: 5, data: 'something', parent_id: 4, children: [] }, { id: 4, data: 'something', parent_id: 3, children: [] }, { id: 3, data: 'something', parent_id: null, children: [] }, { id: 6, data: 'something', parent_id: null, children: [] } ] function buildTree(array) { let tree = [] for (let i = 0; i < array.length; i++) { if (array[i].parent_id) { let parent = array.filter(elem => elem.id === array[i].parent_id).pop() parent.children.push(array[i]) } else { tree.push(array[i]) } } return tree } const tree = buildTree(array) console.log(tree); .as-console-wrapper { min-height: 100% }

从网上复制 http://jsfiddle.net/stywell/k9x2a3g6/

    function list2tree(data, opt) {
        opt = opt || {};
        var KEY_ID = opt.key_id || 'ID';
        var KEY_PARENT = opt.key_parent || 'FatherID';
        var KEY_CHILD = opt.key_child || 'children';
        var EMPTY_CHILDREN = opt.empty_children;
        var ROOT_ID = opt.root_id || 0;
        var MAP = opt.map || {};
        function getNode(id) {
            var node = []
            for (var i = 0; i < data.length; i++) {
                if (data[i][KEY_PARENT] == id) {
                    for (var k in MAP) {
                        data[i][k] = data[i][MAP[k]];
                    }
                    if (getNode(data[i][KEY_ID]) !== undefined) {
                        data[i][KEY_CHILD] = getNode(data[i][KEY_ID]);
                    } else {
                        if (EMPTY_CHILDREN === null) {
                            data[i][KEY_CHILD] = null;
                        } else if (JSON.stringify(EMPTY_CHILDREN) === '[]') {
                            data[i][KEY_CHILD] = [];
                        }
                    }
                    node.push(data[i]);
                }
            }
            if (node.length == 0) {
                return;
            } else {
                return node;
            }
        }
        return getNode(ROOT_ID)
    }

    var opt = {
        "key_id": "ID",              //节点的ID
        "key_parent": "FatherID",    //节点的父级ID
        "key_child": "children",     //子节点的名称
        "empty_children": [],        //子节点为空时,填充的值  //这个参数为空时,没有子元素的元素不带key_child属性;还可以为null或者[],同理
        "root_id": 0,                //根节点的父级ID
        "map": {                     //在节点内映射一些值  //对象的键是节点的新属性; 对象的值是节点的老属性,会赋值给新属性
            "value": "ID",
            "label": "TypeName",
        }
    };

你可以使用npm包数组到树https://github.com/alferov/array-to-tree。 它将普通的节点数组(带有指向父节点的指针)转换为嵌套的数据结构。

解决了从数据库数据集检索到嵌套数据结构(即导航树)的转换问题。

用法:

var arrayToTree = require('array-to-tree');

var dataOne = [
  {
    id: 1,
    name: 'Portfolio',
    parent_id: undefined
  },
  {
    id: 2,
    name: 'Web Development',
    parent_id: 1
  },
  {
    id: 3,
    name: 'Recent Works',
    parent_id: 2
  },
  {
    id: 4,
    name: 'About Me',
    parent_id: undefined
  }
];

arrayToTree(dataOne);

/*
 * Output:
 *
 * Portfolio
 *   Web Development
 *     Recent Works
 * About Me
 */

以防有家长需要。参考id 2，它有多个父元素

const dataSet = [{ "ID": 1, "Phone": "(403) 125-2552", "City": "Coevorden", "Name": "Grady" }, {"ID": 2, "Phone": "(403) 125-2552", "City": "Coevorden", "Name": "Grady" }, { "ID": 3, "parentID": [1,2], "Phone": "(979) 486-1932", "City": "Chełm", "Name": "Scarlet" }]; const expectedDataTree = [ { "ID":1, "Phone":"(403) 125-2552", "City":"Coevorden", "Name":"Grady", "childNodes":[{ "ID":2, "parentID":[1,3], "Phone":"(979) 486-1932", "City":"Chełm", "Name":"Scarlet", "childNodes":[] }] }, { "ID":3, "parentID":[], "Phone":"(403) 125-2552", "City":"Coevorden", "Name":"Grady", "childNodes":[ { "ID":2, "parentID":[1,3], "Phone":"(979) 486-1932", "City":"Chełm", "Name":"Scarlet", "childNodes":[] } ] } ]; const createDataTree = dataset => { const hashTable = Object.create(null); dataset.forEach(aData => hashTable[aData.ID] = {...aData, childNodes: []}); const dataTree = []; dataset.forEach(Datae => { if (Datae.parentID && Datae.parentID.length > 0) { Datae.parentID.forEach( aData => { hashTable[aData].childNodes.push(hashTable[Datae.ID]) }); } else{ dataTree.push(hashTable[Datae.ID]) } }); return dataTree; }; window.alert(JSON.stringify(createDataTree(dataSet)));

类似问题的答案:

https://stackoverflow.com/a/61575152/7388356

更新

你可以使用ES6中引入的Map对象。基本上，你不再通过遍历数组来寻找父元素，你只需要从数组中通过父元素的id来获取父元素就像你在数组中通过索引来获取元素一样。

下面是一个简单的例子:

const people = [
  {
    id: "12",
    parentId: "0",
    text: "Man",
    level: "1",
    children: null
  },
  {
    id: "6",
    parentId: "12",
    text: "Boy",
    level: "2",
    children: null
  },
  {
    id: "7",
    parentId: "12",
    text: "Other",
    level: "2",
    children: null
  },
  {
    id: "9",
    parentId: "0",
    text: "Woman",
    level: "1",
    children: null
  },
  {
    id: "11",
    parentId: "9",
    text: "Girl",
    level: "2",
    children: null
  }
];

function toTree(arr) {
  let arrMap = new Map(arr.map(item => [item.id, item]));
  let tree = [];

  for (let i = 0; i < arr.length; i++) {
    let item = arr[i];

    if (item.parentId !== "0") {
      let parentItem = arrMap.get(item.parentId);

      if (parentItem) {
        let { children } = parentItem;

        if (children) {
          parentItem.children.push(item);
        } else {
          parentItem.children = [item];
        }
      }
    } else {
      tree.push(item);
    }
  }

  return tree;
}

let tree = toTree(people);

console.log(tree);

使用ES6方法。工作很有魅力

//数据集 //一个顶级注释 Const注释= [{ id: 1、 parent_id:零 }, { id: 2 parent_id: 1 }, { id: 3, parent_id: 1 }, { id: 4 parent_id: 2 }, { id: 5 parent_id: 4 }); Const nest = (items, id = null, link = 'parent_id') => 项目 .filter(item => item[link] === id) .map(item =>({…Item, children: nest(items, Item .id)})); console.log ( 巢(评论) ）