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2025-04-01 05:00:04

在javascript中从平面数组构建树数组

我有一个复杂的json文件，我必须处理javascript使其分层，以便稍后构建树。 json的每个条目都有: Id:唯一的Id， parentId:父节点的id(如果节点是树的根，则为0) Level:树的深度级别

json数据已经“有序”。我的意思是，一个条目在它上面有一个父节点或兄弟节点，在它下面有一个子节点或兄弟节点。

输入:

{
    "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
        }
    ],
    "Animals": [
        {
            "id": "5",
            "parentId": "0",
            "text": "Dog",
            "level": "1",
            "children": null
        },
        {
            "id": "8",
            "parentId": "5",
            "text": "Puppy",
            "level": "2",
            "children": null
        },
        {
            "id": "10",
            "parentId": "13",
            "text": "Cat",
            "level": "1",
            "children": null
        },
        {
            "id": "14",
            "parentId": "13",
            "text": "Kitten",
            "level": "2",
            "children": null
        },
    ]
}

预期产量:

{
    "People": [
        {
            "id": "12",
            "parentId": "0",
            "text": "Man",
            "level": "1",
            "children": [
                {
                    "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":
            {

                "id": "11",
                "parentId": "9",
                "text": "Girl",
                "level": "2",
                "children": null
            }
        }

    ],    

    "Animals": [
        {
            "id": "5",
            "parentId": "0",
            "text": "Dog",
            "level": "1",
            "children": 
                {
                    "id": "8",
                    "parentId": "5",
                    "text": "Puppy",
                    "level": "2",
                    "children": null
                }
        },
        {
            "id": "10",
            "parentId": "13",
            "text": "Cat",
            "level": "1",
            "children": 
            {
                "id": "14",
                "parentId": "13",
                "text": "Kitten",
                "level": "2",
                "children": null
            }
        }

    ]
}

当前回答

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)));

2021-01-08 09:08:38

其他回答

更新2022

这是一个针对无序项的建议。该函数使用单个循环和哈希表，并收集所有带有id的项。如果找到根节点，则将该对象添加到结果数组中。

const getTree = (data, root) => { const t = {}; data.forEach(o => ((t[o.parentId] ??= {}).children ??= []).push(Object.assign(t[o.id] ??= {}, o))); return t[root].children; }, data = { 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 }], Animals: [{ id: "5", parentId: "0", text: "Dog", level: "1", children: null }, { id: "8", parentId: "5", text: "Puppy", level: "2", children: null }, { id: "10", parentId: "13", text: "Cat", level: "1", children: null }, { id: "14", parentId: "13", text: "Kitten", level: "2", children: null }] }, result = Object.fromEntries(Object .entries(data) .map(([k, v]) => [k, getTree(v, '0')]) ); console.log(result); .as-console-wrapper { max-height: 100% !important; top: 0; }

2017-01-14 16:56:04

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% }

2021-12-01 18:38:59

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)));

2021-01-08 09:08:38

它可能是有用的包列表到树 安装:

bower install list-to-tree --save

or

npm install list-to-tree --save

例如，有列表:

var list = [
  {
    id: 1,
    parent: 0
  }, {
    id: 2,
    parent: 1
  }, {
    id: 3,
    parent: 1
  }, {
    id: 4,
    parent: 2
  }, {
    id: 5,
    parent: 2
  }, {
    id: 6,
    parent: 0
  }, {
    id: 7,
    parent: 0
  }, {
    id: 8,
    parent: 7
  }, {
    id: 9,
    parent: 8
  }, {
    id: 10,
    parent: 0
  }
];

使用包列表到树:

var ltt = new LTT(list, {
  key_id: 'id',
  key_parent: 'parent'
});
var tree = ltt.GetTree();

结果:

[{
  "id": 1,
  "parent": 0,
  "child": [
    {
      "id": 2,
      "parent": 1,
      "child": [
        {
          "id": 4,
          "parent": 2
        }, {
          "id": 5, "parent": 2
        }
      ]
    },
    {
      "id": 3,
      "parent": 1
    }
  ]
}, {
  "id": 6,
  "parent": 0
}, {
  "id": 7,
  "parent": 0,
  "child": [
    {
      "id": 8,
      "parent": 7,
      "child": [
        {
          "id": 9,
          "parent": 8
        }
      ]
    }
  ]
}, {
  "id": 10,
  "parent": 0
}];
2015-09-01 07:38:09

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);

2020-05-03 13:29:27

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