我喜欢@WilliamLeung的纯JavaScript解决方案，但有时你需要在现有数组中进行更改，以保持对对象的引用。

function listToTree(data, options) {
  options = options || {};
  var ID_KEY = options.idKey || 'id';
  var PARENT_KEY = options.parentKey || 'parent';
  var CHILDREN_KEY = options.childrenKey || 'children';

  var item, id, parentId;
  var map = {};
    for(var i = 0; i < data.length; i++ ) { // make cache
    if(data[i][ID_KEY]){
      map[data[i][ID_KEY]] = data[i];
      data[i][CHILDREN_KEY] = [];
    }
  }
  for (var i = 0; i < data.length; i++) {
    if(data[i][PARENT_KEY]) { // is a child
      if(map[data[i][PARENT_KEY]]) // for dirty data
      {
        map[data[i][PARENT_KEY]][CHILDREN_KEY].push(data[i]); // add child to parent
        data.splice( i, 1 ); // remove from root
        i--; // iterator correction
      } else {
        data[i][PARENT_KEY] = 0; // clean dirty data
      }
    }
  };
  return data;
}

Exapmle: https://jsfiddle.net/kqw1qsf0/17/

我已经编写了一个测试脚本来评估用户shekhardtu(见答案)和FurkanO(见答案)提出的两种最通用的解决方案的性能(意味着输入不需要事先排序，代码不依赖于第三方库)。

http://playcode.io/316025?tabs=console&script.js&output

FurkanO的解决方案似乎是最快的。

/* ** performance test for https://stackoverflow.com/questions/18017869/build-tree-array-from-flat-array-in-javascript */ // Data Set (e.g. nested comments) var comments = [{ id: 1, parent_id: null }, { id: 2, parent_id: 1 }, { id: 3, parent_id: 4 }, { id: 4, parent_id: null }, { id: 5, parent_id: 4 }]; // add some random entries let maxParentId = 10000; for (let i=6; i<=maxParentId; i++) { let randVal = Math.floor((Math.random() * maxParentId) + 1); comments.push({ id: i, parent_id: (randVal % 200 === 0 ? null : randVal) }); } // solution from user "shekhardtu" (https://stackoverflow.com/a/55241491/5135171) const nest = (items, id = null, link = 'parent_id') => items .filter(item => item[link] === id) .map(item => ({ ...item, children: nest(items, item.id) })); ; // solution from user "FurkanO" (https://stackoverflow.com/a/40732240/5135171) const createDataTree = dataset => { let hashTable = Object.create(null) dataset.forEach( aData => hashTable[aData.id] = { ...aData, children : [] } ) let dataTree = [] dataset.forEach( aData => { if( aData.parent_id ) hashTable[aData.parent_id].children.push(hashTable[aData.id]) else dataTree.push(hashTable[aData.id]) } ) return dataTree }; /* ** lets evaluate the timing for both methods */ let t0 = performance.now(); let createDataTreeResult = createDataTree(comments); let t1 = performance.now(); console.log("Call to createDataTree took " + Math.floor(t1 - t0) + " milliseconds."); t0 = performance.now(); let nestResult = nest(comments); t1 = performance.now(); console.log("Call to nest took " + Math.floor(t1 - t0) + " milliseconds."); //console.log(nestResult); //console.log(createDataTreeResult); // bad, but simple way of comparing object equality console.log(JSON.stringify(nestResult)===JSON.stringify(createDataTreeResult));

Based on @FurkanO's answer, I created another version that does not mutate the origial data (like @Dac0d3r requested). I really liked @shekhardtu's answer, but realized it had to filter through the data many times. I thought a solution could be to use FurkanO's answer by copying the data first. I tried my version in jsperf, and the results where unfortunately (very) bleak... It seems like the accepted answer is really a good one! My version is quite configurable and failsafe though, so I share it with you guys anyway; here is my contribution:

function unflat(data, options = {}) {
    const { id, parentId, childrenKey } = {
        id: "id",
        parentId: "parentId",
        childrenKey: "children",
        ...options
    };
    const copiesById = data.reduce(
        (copies, datum) => ((copies[datum[id]] = datum) && copies),
        {}
    );
    return Object.values(copiesById).reduce(
        (root, datum) => {
            if ( datum[parentId] && copiesById[datum[parentId]] ) {
                copiesById[datum[parentId]][childrenKey] = [ ...copiesById[datum[parentId]][childrenKey], datum ];
            } else {
                root = [ ...root, datum ];
            }
            return root
        }, []
    );
}

const data = [
    {
        "account": "10",
        "name": "Konto 10",
        "parentAccount": null
    },{
        "account": "1010",
        "name": "Konto 1010",
        "parentAccount": "10"
    },{
        "account": "10101",
        "name": "Konto 10101",
        "parentAccount": "1010"
    },{
        "account": "10102",
        "name": "Konto 10102",
        "parentAccount": "1010"
    },{
        "account": "10103",
        "name": "Konto 10103",
        "parentAccount": "1010"
    },{
        "account": "20",
        "name": "Konto 20",
        "parentAccount": null
    },{
        "account": "2020",
        "name": "Konto 2020",
        "parentAccount": "20"
    },{
        "account": "20201",
        "name": "Konto 20201",
        "parentAccount": "2020"
    },{
        "account": "20202",
        "name": "Konto 20202",
        "parentAccount": "2020"
    }
];

const options = {
    id: "account",
    parentId: "parentAccount",
    childrenKey: "children"
};

console.log(
    "Hierarchical tree",
    unflat(data, options)
);

通过options参数，可以配置将哪个属性用作id或父id。也可以配置children属性的名称，如果有人想要“childNodes”:[]或其他什么。

OP可以简单地使用默认选项:

input.People = unflat(input.People);

如果父对象id是假的(null, undefined或其他假的值)或父对象不存在，我们认为该对象是根节点。

这是一个旧线程，但我认为更新永远不会伤害，与ES6你可以做到:

const data = [{ id: 1, parent_id: 0 }, { id: 2, parent_id: 1 }, { id: 3, parent_id: 1 }, { id: 4, parent_id: 2 }, { id: 5, parent_id: 4 }, { id: 8, parent_id: 7 }, { id: 9, parent_id: 8 }, { id: 10, parent_id: 9 }]; const arrayToTree = (items=[], id = null, link = 'parent_id') => items.filter(item => id==null ? !items.some(ele=>ele.id===item[link]) : item[link] === id ).map(item => ({ ...item, children: arrayToTree(items, item.id) })) const temp1=arrayToTree(data) console.log(temp1) const treeToArray = (items=[], key = 'children') => items.reduce((acc, curr) => [...acc, ...treeToArray(curr[key])].map(({ [`${key}`]: child, ...ele }) => ele), items); const temp2=treeToArray(temp1) console.log(temp2)

希望它能帮助到别人

有同样的问题，但我不能确定数据是否已排序。我不能使用第三方库，所以这只是香草Js;输入数据可以从@Stephen的例子中获取;

var arr = [ {'id':1 ,'parentid' : 0}, {'id':4 ,'parentid' : 2}, {'id':3 ,'parentid' : 1}, {'id':5 ,'parentid' : 0}, {'id':6 ,'parentid' : 0}, {'id':2 ,'parentid' : 1}, {'id':7 ,'parentid' : 4}, {'id':8 ,'parentid' : 1} ]; function unflatten(arr) { var tree = [], mappedArr = {}, arrElem, mappedElem; // First map the nodes of the array to an object -> create a hash table. for(var i = 0, len = arr.length; i < len; i++) { arrElem = arr[i]; mappedArr[arrElem.id] = arrElem; mappedArr[arrElem.id]['children'] = []; } for (var id in mappedArr) { if (mappedArr.hasOwnProperty(id)) { mappedElem = mappedArr[id]; // If the element is not at the root level, add it to its parent array of children. if (mappedElem.parentid) { mappedArr[mappedElem['parentid']]['children'].push(mappedElem); } // If the element is at the root level, add it to first level elements array. else { tree.push(mappedElem); } } } return tree; } var tree = unflatten(arr); document.body.innerHTML = "<pre>" + (JSON.stringify(tree, null, " "))

JS小提琴

平面阵列到树

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)));