js数组转换tree树状结构数组转成对象代码实现对象转成数组代码实现数组转成树代码实现年纪轻轻多敲敲代码

数组转成对象

const arr = [ { label: '男', value: 0 }, 
              { label: '女', value: 1 } ] 
             // 转换为： {0: '男', 1:'女'}

代码实现

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <script>
      const arr = [
        { label: '男', value: 0 },
        { label: '女', value: 1 }
      ]
      function fu(arr) {
        // reduce
        return arr.reduce((sum, item) => {
          // 利用对象的新增，给对象传值
          sum[item['value']] = item['label']
          return sum
        }, {})
      }
      const obj = fu(arr) // obj ===> {0: '男', 1:'女'}
      console.log(obj)
    </script>
  </body>
</html>

对象转成数组

const obj = { 0: '男', 1: '女' } 
//转换为： 
[{label: '男', value: 0},
 {label: '女', value: 1}
]

代码实现

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <script>
      const obj = { 0: '男', 1: '女' }
      function fu(obj) {
        // 写代码
        let arr = [] // 由于最终结果要的是一个数组，所以先定义一个空数组
        let newObj = {} // 数组里面的每一项是个对象，所以定义一个空对象
        for (let key in obj) {
          // 遍历参数对象，把对应的键传给定义的对象的 value ，把对应的值给定义的 label
          newObj = { label: obj[key], value: key * 1 }
          // 把得到的新对象添加到定义好的空数组中
          arr.push(newObj)
        }
        // return 最后的结果
        return arr
      }
      const arr = fu(obj) // arr ===>  [{label: '男', value: 0},{label: '女', value: 1}]
      console.log(arr)
    </script>
  </body>
</html>

数组转成树

const  data = 
[
  {id:"01", name: "张大大", pid:"", job: "项目经理"},
  {id:"02", name: "小亮", pid:"01", job: "产品leader"},
  {id:"03", name: "小美", pid:"01", job: "UIleader"},
  {id:"04", name: "老马", pid:"01", job: "技术leader"},
  {id:"05", name: "老王", pid:"01", job: "测试leader"},
  {id:"06", name: "老李", pid:"01", job: "运维leader"},
  {id:"07", name: "小丽", pid:"02", job: "产品经理"},
  {id:"08", name: "大光", pid:"02", job: "产品经理"},
  {id:"09", name: "小高", pid:"03", job: "UI设计师"},
  {id:"10", name: "小刘", pid:"04", job: "前端工程师"},
  {id:"11", name: "小华", pid:"04", job: "后端工程师"},
  {id:"12", name: "小李", pid:"04", job: "后端工程师"},
  {id:"13", name: "小赵", pid:"05", job: "测试工程师"},
  {id:"14", name: "小强", pid:"05", job: "测试工程师"},
  {id:"15", name: "小涛", pid:"06", job: "运维工程师"}
]
转换为：
data: [{
        label: '张大大',
        children: [
          {
          	label: '小亮',
          	children: [{label: '小丽'}，{label: '大光'}]
        	},
          {
          	label: '小美',
          	children: [{label: '小高'}]
        	},
          {
          	label: '老马',
          	children: [{label: '小刘'}，{label: '小华'},{label: '小李'}]
        	},
          {
          	label: '老王',
          	children: [{label: '小赵'}，{label: '小强'}]
        	},
          {
          	label: '老李',
          	children: [{label: '小涛'}]
        	}
      	]
      }]

代码实现

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <script>
      const data = [
        { id: '01', name: '张大大', pid: '', job: '项目经理' },
        { id: '02', name: '小亮', pid: '01', job: '产品leader' },
        { id: '03', name: '小美', pid: '01', job: 'UIleader' },
        { id: '04', name: '老马', pid: '01', job: '技术leader' },
        { id: '05', name: '老王', pid: '01', job: '测试leader' },
        { id: '06', name: '老李', pid: '01', job: '运维leader' },
        { id: '07', name: '小丽', pid: '02', job: '产品经理' },
        { id: '08', name: '大光', pid: '02', job: '产品经理' },
        { id: '09', name: '小高', pid: '03', job: 'UI设计师' },
        { id: '10', name: '小刘', pid: '04', job: '前端工程师' },
        { id: '11', name: '小华', pid: '04', job: '后端工程师' },
        { id: '12', name: '小李', pid: '04', job: '后端工程师' },
        { id: '13', name: '小赵', pid: '05', job: '测试工程师' },
        { id: '14', name: '小强', pid: '05', job: '测试工程师' },
        { id: '15', name: '小涛', pid: '06', job: '运维工程师' }
      ]

      // 完成代码
      function arrToTree(data) {
        // 你的代码
        // 先把传进来的数据的 name 修改为 label 再删除 name
        data.map(item => {
          item.label = item.name
          delete item.name
        })
        // 声明空数组 接收最后的结果
        let arr = []
        // 定义空对象 接收每个人的信息并准备划分层级
        let obj = {}
        // 判断传送进来的值是否为数组，可以使用Array.isArray()方法判断，也可以用instanceof Array 进行判断
        if (!(data instanceof Array)) {
          return arr
        }
        // 循环 data 先把所有的数据放进一个对象里
        data.forEach(item => {
          obj[item.id] = item
        })
        // 定义遍历删除id、job、pid的方法
        function del(del) {
          return del.forEach(i => {
            delete i.id
            delete i.job
            delete i.pid
          })
        }
        data.forEach(item => {
          if (obj[item.pid]) {
            if (obj[item.pid].children) {
              obj[item.pid].children.push(item)
              // 遍历删除id、job、pid
              del(obj[item.pid].children)
            } else {
              ;(obj[item.pid].children = []).push(item)
              del(obj[item.pid].children)
            }
          } else {
            arr.push(item)
            del(arr)
          }
        })
        return arr
      }
      // 目标：
      const treeData = arrToTree(data)
      console.log(treeData)
    </script>
  </body>
</html>