// js实现树级递归，

// 通过js生成tree树形菜单(递归算法)

const data = [

  { id: 1, name: "办公管理", pid: 0 },

  { id: 2, name: "请假申请", pid: 1 },

  { id: 3, name: "出差申请", pid: 1 },

  { id: 4, name: "请假记录", pid: 2 },

  { id: 5, name: "系统设置", pid: 0 },

  { id: 6, name: "权限管理", pid: 5 },

  { id: 7, name: "用户角色", pid: 6 },

  { id: 8, name: "菜单设置", pid: 6 },

  ];

function toTree(data){

  const map = {};

  data.forEach(item => {

    map[item.id] = {...item};

  });

  const result= [];

  data.forEach((item)=>{

    const parent = map[item.pid];

    if(parent){

      if(!parent.children) parent.children =[];

      parent.children.push(item);

    }else{

      result.push(item);

    }

  })

  return result;

}

console.log(toTree(data));