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

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",
        }
    };

其他回答

我的typescript解决方案,可能对你有帮助:

type ITreeItem<T> = T & {
    children: ITreeItem<T>[],
};

type IItemKey = string | number;

function createTree<T>(
    flatList: T[],
    idKey: IItemKey,
    parentKey: IItemKey,
): ITreeItem<T>[] {
    const tree: ITreeItem<T>[] = [];

    // hash table.
    const mappedArr = {};
    flatList.forEach(el => {
        const elId: IItemKey = el[idKey];

        mappedArr[elId] = el;
        mappedArr[elId].children = [];
    });

    // also you can use Object.values(mappedArr).forEach(...
    // but if you have element which was nested more than one time
    // you should iterate flatList again:
    flatList.forEach((elem: ITreeItem<T>) => {
        const mappedElem = mappedArr[elem[idKey]];

        if (elem[parentKey]) {
            mappedArr[elem[parentKey]].children.push(elem);
        } else {
            tree.push(mappedElem);
        }
    });

    return tree;
}

用法示例:

createTree(yourListData, 'id', 'parentId');

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) )

我根据@Halcyon的答案写了一个ES6版本

const array = [
  {
    id: '12',
    parentId: '0',
    text: 'one-1'
  },
  {
    id: '6',
    parentId: '12',
    text: 'one-1-6'
  },
  {
    id: '7',
    parentId: '12',
    text: 'one-1-7'
  },

  {
    id: '9',
    parentId: '0',
    text: 'one-2'
  },
  {
    id: '11',
    parentId: '9',
    text: 'one-2-11'
  }
];

// Prevent changes to the original data
const arrayCopy = array.map(item => ({ ...item }));

const listToTree = list => {
  const map = {};
  const roots = [];

  list.forEach((v, i) => {
    map[v.id] = i;
    list[i].children = [];
  });

  list.forEach(v => (v.parentId !== '0' ? list[map[v.parentId]].children.push(v) : roots.push(v)));

  return roots;
};

console.log(listToTree(arrayCopy));

该算法的原理是利用“map”建立索引关系。通过“parentId”可以很容易地在列表中找到“item”,并为每个“item”添加“children”,因为“list”是一个引用关系,所以“roots”将与整个树建立关系。

你可以用两行代码来解决这个问题:

_(flatArray).forEach(f=>
           {f.nodes=_(flatArray).filter(g=>g.parentId==f.id).value();});

var resultArray=_(flatArray).filter(f=>f.parentId==null).value();

在线测试(查看浏览器控制台以获得创建的树)

要求:

1-安装lodash 4(一个Javascript库,用于操作对象和集合,使用性能方法=>,就像c#中的Linq)

2-如下所示的flatArray:

    var flatArray=
    [{
      id:1,parentId:null,text:"parent1",nodes:[]
    }
   ,{
      id:2,parentId:null,text:"parent2",nodes:[]
    }
    ,
    {
      id:3,parentId:1,text:"childId3Parent1",nodes:[]
    }
    ,
    {
      id:4,parentId:1,text:"childId4Parent1",nodes:[]
    }
    ,
    {
      id:5,parentId:2,text:"childId5Parent2",nodes:[]
    }
    ,
    {
      id:6,parentId:2,text:"childId6Parent2",nodes:[]
    }
    ,
    {
      id:7,parentId:3,text:"childId7Parent3",nodes:[]
    }
    ,
    {
      id:8,parentId:5,text:"childId8Parent5",nodes:[]
    }];

谢谢Bakhshabadi先生

祝你好运

如果使用地图查找,就有一个有效的解决方案。如果父母总是在他们的孩子之前,你可以合并两个for循环。它支持多个根。它在悬垂的分支上给出一个错误,但可以修改为忽略它们。它不需要第三方库。就我所知,这是最快的解决方法。

function list_to_tree(list) { var map = {}, node, roots = [], i; for (i = 0; i < list.length; i += 1) { map[list[i].id] = i; // initialize the map list[i].children = []; // initialize the children } for (i = 0; i < list.length; i += 1) { node = list[i]; if (node.parentId !== "0") { // if you have dangling branches check that map[node.parentId] exists list[map[node.parentId]].children.push(node); } else { roots.push(node); } } return roots; } var entries = [{ "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 } ]; console.log(list_to_tree(entries));

如果你喜欢复杂性理论,这个解决方案是Θ(n log(n))。递归过滤器的解决方案是Θ(n^2),这对于大型数据集可能是一个问题。