javascript - 怎么根据id递归多维数组？

Question

,该数组是一维数组，第一层节点是parent:# 第二层根据第一层id和
第二层parent进行比较，以此类推

Answer 1

var a:any = [{ id: 1, name: 3, pid: -1, children: [] }];
const map = new Map();

// 将所有的记录以下方便取
for (const t of a) {
map.set(t.id, t);
t.children = [];
}

// 遍历添加子元素
for (const t of a) {
if (t.pid !== -1) {

const e = map.get(t.pid);
e.children.push(e);

}
}

console.log(map);

// 从map里面去除pid为

var a = [
  { id: "-1", parent: "#", text: "1" },
  { id: "1", parent: "#", text: "2" },
  { id: "2", parent: "4", text: "3" },
  { id: "3", parent: "2", text: "4" },
  { id: "4", parent: "6", text: "5" },
];
const map = new Map();

// 将所有的记录以下方便取
for (const t of a) {
  map.set(t.id, t);
  t.children = [];
}
map.forEach((t) => {
  if (t.parent !== "#") {
    const parent = map.get(t.parent);
    if (parent) {
      parent.children.push(t);
    }
  }
});
const result = [];
map.forEach((e) => {
    result.push(e);
});

console.log(result);

// 从map里面去除pid为

Answer 2

function toTree(data) {
    const res = [];
    const map = {};
    data.forEach((item) => {
        map[item.id] = item
    })
    data.forEach((item) => {
        let parentItem = map[item.parent];
        if(parentItem) {
            (parentItem.children || (parentItem.children = [])).push(item)
        } else {
            res.push(item)
        }
    })
    return res
}

Answer 3

var arr = [
      { id: '-1', parent: '#', text: '1' },
      { id: '1', parent: '#', text: '2' },
      { id: '2', parent: '4', text: '3' },
      { id: '3', parent: '2', text: '4' },
      { id: '4', parent: '6', text: '5' }
];
console.log(sum(0, arr));

function sum(index,data) {
      if(!data[index+1]) return 'no';
      if(data[index].id == data[index+1].parent) return data[index+1];
      return sum(index+1,data);
}

Answer 4

let arr = [{id:"-1",parent:"#",text:'请选择'},{id:"1",parent:"#",text:'刑事'},{id:"2",parent:"1",text:'安全罪'}];
let arrToTree =(arr, parent='#')=> {
    let obj = arr.reduce((acc,cur)=>{
       // 根据parent 判断是否相等来归类。true 当前级别
        acc[cur.parent == parent].push(cur);
        return acc;
    },{true:[],false:[]})
    // 当前级别
    let currentArr = obj[true];
     // 其他级别
    let otherArr = obj[false];
   return currentArr.map(item=>{
       // 递归得到子级
        let children = arrToTree(otherArr, item.id);
        return {...item, children};
    })
}
arrToTree(arr, '#');