javascript - 在深度级别的基础上链接 child 和 parent

Question

我的所有父子都在一个数组数据中。我想要的是在每个对象上添加一个新属性(级别)。

假设我有数据

 var data = [
        {
            id: 1,
            parent_id: 0,
            name: "Child1",
        },
        {
            id: 4,
            parent_id: 1,
            name: "Child11",

        },

        {
            id: 5,
            parent_id: 4,
            name: "Child111",
        },
        {
            id: 11,
            parent_id: 4,
            name: "Child112"
        },


        {
            id: 13,
            parent_id: 11,
            name: "Child1121",
        },

        {
            id: 21,
            parent_id: 11,
            name: "Child1122"
        },
        {
            id: 22,
            parent_id: 11,
            name: "Child1123"
        },
        {
            id: 24,
            parent_id: 1,
            name: 'Child12'
        }

    ]

我想要一个基于 child 的 parent_id 的child-parent 关系，并在数组的每个对象中分配一个新属性作为表示深度级别的级别 child 基于其 parent 。我的预期结果是:

var data = [
            {
                id: 1,
                parent_id: 0, <-------represents root 
                name: "Child1",
                level:0   <--------level based on its parent_id 
            },
            {
                id: 4,
                parent_id: 1
                name: "Child11",
                level:1

            },
            {
                id: 5,
                parent_id: 4,
                name: "Child111",
                level:2
            },
            {
                id: 11,
                parent_id: 4,
                name: "Child112",
                level:2
            },


            {
                id: 13,
                parent_id: 11,
                name: "Child1121",
                level:3
            },

            {
                id: 21,
                parent_id: 11,
                name: "Child1122",
                level:3
            },
            {
                id: 22,
                parent_id: 11,
                name: "Child1123",
                level:3
            },
            {
                id: 24,
                parent_id: 1,
                name: 'Child12',
                level:1
            }

        ]

我的代码

 function buildTree(elements, parent_id, level = 0) {

                elements.forEach(element => {


                    if (element['parent_id'] == parent_id) {
                        console.log('parent_id', parent_id);
                        // elements.filter(item=>item!==element);
                        element['level'] = level;

                    }
                    else{
                        buildTree(elements,parent_id,level+1);
                    }





                })




            return elements;




        }

Answer 1

对于已排序的数据，您可以为级别计数取一个对象并映射一个新的数据集。

var data = [{ id: 1, parent_id: 0, name: "Child1" }, { id: 4, parent_id: 1, name: "Child11" }, { id: 5, parent_id: 4, name: "Child111" }, { id: 11, parent_id: 4, name: "Child112" }, { id: 13, parent_id: 11, name: "Child1121" }, { id: 21, parent_id: 11, name: "Child1122" }, { id: 22, parent_id: 11, name: "Child1123" }, { id: 24, parent_id: 1, name: 'Child12' }],
    levels = {},
    result = data.map(o => ({
        ...o,
        level: levels[o.id] = o.parent_id in levels
            ? levels[o.parent_id] + 1
            : 0
    }));

console.log(result);

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