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JS中的树形数据结构处理
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树形数据的一些相关处理方法
// 用于测试的树形数据
const treeData = [
{
id: '1',
name: '测试1',
pId: '0',
children: [
{
id: '11',
name: '测试11',
pId: '1',
children: [
{
id: '111',
name: '测试111',
pId: '11',
children: [
{
id: '1111',
name: '测试1111',
pId: '111',
},
{
id: '1112',
name: '测试1112',
pId: '111',
}
]
},
{
id: '112',
name: '测试112',
pId: '11',
children: [
{
id: '1121',
name: '测试1121',
pId: '112',
}
]
},
{
id: '113',
name: '测试113',
pId: '11',
},
]
},
{
id: '12',
name: '测试12',
pId: '1',
children: [
{
id: '121',
name: '测试121',
pId: '12',
}
]
},
{
id: '13',
name: '测试13',
pId: '1'
},
{
id: '14',
name: '测试14',
pId: '1'
}
]
},
{
id: '2',
name: '测试2',
pId: '0',
children: [
{
id: '21',
name: '测试21',
pId: '2',
children: [
{
id: '211',
name: '测试211',
pId: '21',
},
{
id: '212',
name: '测试212',
pId: '21',
}
]
},
{
id: '22',
name: '测试22',
pId: '2'
},
]
}
]
1. 递归查找当前节点
方法1：forEach + 回调
function findRecursion (data, key, callback) {
data.forEach((item, index, arr) => {
if (item.id === key) {
return callback(item, index, arr)
}
if (item.children) {
return findRecursion(item.children, key, callback)
}
})
}
// 查找 测试1112(1112)
findRecursion(treeData, '1112', (item, index, arr) => {
console.log('1. 递归查找当前节点:', item, index, arr)
})
方法2：for循环
function getCurrentNode (data, key) {
let temp = null
for (let i = 0; i < data.length; i++) {
if (data[i].id === key) {
temp = data[i]
break
} else if (data[i].children?.length) {
const o = getCurrentNode(data[i].children, key)
if (o) {
temp = o
break
}
}
}
return temp
}
const cInfo1 = getCurrentNode(treeData, '1112')
console.log('1. 递归查找当前节点 (2) 1112:', cInfo1)
const cInfo2 = getCurrentNode(treeData, '212')
console.log('1. 递归查找当前节点 (2) 212:', cInfo2)
const cInfo3 = getCurrentNode(treeData, '888')
console.log('1. 递归查找当前节点 (2) 888:', cInfo3)
2. 递归获取当前节点及以下的所有节点id
function getChildId (data, idArr) {
data.forEach(item => {
if (item.id) {
idArr.push(item.id)
}
if (item.children) {
getChildId(item.children, idArr)
}
})
return idArr
}
// 获取 treeData此树以下的所有节点id
const idArr = getChildId(treeData, [])
console.log('2. 获取当前节点及以下的所有节点id', idArr)
3. 递归判断所有后代节点中有无此节点中的一个
function judgeChildrenHad (data, keys) {
let mark = false
const fn = (data, keys) => {
for (let i = 0; i < data.length; i++) {
if (keys.includes(data[i].id)) {
mark = true
} else if (data[i].children?.length) {
fn(data[i].children, keys)
}
}
}
fn(data, keys)
return mark
}
// 判断 treeData后代节点中有无 测试1112(1112)节点
const mark1 = judgeChildrenHad(treeData, ['1112'])
console.log('3. mark1', mark1)
// 判断 treeData后代节点中有无 测试1121(1121)节点
const mark2 = judgeChildrenHad(treeData, ['1121'])
console.log('3. mark2', mark2)
// 判断 treeData后代节点中有无 测试888(888)节点
const mark3 = judgeChildrenHad(treeData, ['888'])
console.log('3. mark3', mark3)
4. 树形数据扁平化
方法1：广度优先遍历
function treeToFlat (data) {
let queue = []
let result = []
queue = queue.concat(JSON.parse(JSON.stringify(data)))
while (queue.length) {
const firstItem = queue.shift()
if (firstItem.children) {
queue = queue.concat(firstItem.children)
Reflect.deleteProperty(firstItem, 'children')
}
result.push(firstItem)
}
return result
}
console.log('4. 树形数据扁平化 方法1：广度优先遍历', treeToFlat(treeData))
方法2：递归
function treeToFlat2(data) {
const result = []
data.forEach(item => {
const obj = {
name: item.name,
id: item.id,
pId: item.pId
}
result.push(obj)
if (item.children?.length) {
result.push(...treeToFlat2(item.children, item.id))
}
})
return result
}
const res1 = treeToFlat2(treeData)
console.log('4. 树形数据扁平化 方法2：递归', res1)
5. 扁平化数据转树形结构
方法1：Map对象
function flatToTree (data) {
const result = []
const itemMap = {}
for (const item of data) {
const id = item.id
const pId = item.pId
if (itemMap[id]) {
itemMap[id] = {
...itemMap[id],
...item
}
} else {
itemMap[id] = { ...item }
}
const treeItem = itemMap[id]
if (!pId || pId === '0') {
result.push(treeItem)
} else {
if (!itemMap[pId]) {
itemMap[pId] = {
children: []
}
}
if (!itemMap[pId].children) {
itemMap[pId].children = []
}
itemMap[pId].children.push(treeItem)
}
}
return result
}
const r = JSON.parse(JSON.stringify(res1))
r.unshift({
id: '999',
name: 'yyyyy',
pId: '1'
})
const res2 = flatToTree(r)
console.log('5. 扁平化数据转树形数据结构 方法1：Map对象', res2)
方法2：递归
function flatToTree2 (data) {
const result = []
const fn = (arr, cArr, pId = '0') => {
for (let i = 0; i< arr.length; i++) {
const item = { ...arr[i], children: [] }
if (arr[i].pId === pId) {
cArr.push(item)
fn(arr, item.children, arr[i].id)
}
}
}
fn(data, result)
return result
}
const r2 = JSON.parse(JSON.stringify(res1))
r2.unshift({
id: '999',
name: 'yyyyy',
pId: '1'
})
console.log('5. 扁平化数据转树形数据结构 方法2：递归', flatToTree2(r2))
6. 查找当前节点的父节点
function getParentNode (data, key) {
let result = null
for (let i = 0; i < data.length; i++) {
if (data[i].children?.length) {
if (data[i].children.some(item => item.id === key)) {
result = data[i]
break
} else {
const temp = getParentNode(data[i].children, key)
if (temp) {
result = temp
break
}
}
}
}
return result
}
const pResult1 = getParentNode(treeData, '1111')
console.log('6、查找当前节点的父节点 1111: ', pResult1)
const pResult2 = getParentNode(treeData, '212')
console.log('6、查找当前节点的父节点 212: ', pResult2)
const pResult3 = getParentNode(treeData, '888')
console.log('6、查找当前节点的父节点 888: ', pResult3)
7. 查找当前节点的所有直系祖先节点（例：当前节点：1111，所有祖先节点为：111,11,1）
function getAllParentNode (data, key) {
const arr = []
const fn = (data, key) => {
const p = getParentNode(data, key)
if (p && p.id) {
arr.push(p)
fn(data, p.id)
}
}
fn(data, key)
return arr
}
const pArr1 = getAllParentNode(treeData, '1121')
console.log('7、查找当前节点的所有祖先节点 1121:', pArr1)
const pArr2 = getAllParentNode(treeData, '212')
console.log('7、查找当前节点的所有祖先节点 212:', pArr2)
8. 获取树形数据的最深层级数字
function getDeepRank (data) {
let deepRank = 0
const fn = (arr, num = 0) => {
for (let i = 0; i < arr.length; i++) {
let rank = num || num + 1
deepRank = Math.max(deepRank, rank)
if (arr[i].children?.length) {
fn(arr[i].children, rank + 1)
}
}
}
fn(data)
return deepRank
}
console.log('8. 获取树形数据的最深层级数字:', getDeepRank(treeData))
