用递归实现多维数遍历并给树结构添加字段

操作数据

 jsonArr =  [ {
    "departmentId": "1",
    "name": "中国",
    "departmentList": [
        {
            "departmentId": "49",
            "name": "湖南",
            "departmentList": [
                {
                    "departmentId": "50",
                    "name": "娄底",
                    "departmentList": [
                        {
                            "departmentId": "54",
                            "name": "双峰",
                            "departmentList": []
                        }
                     ]
                },
                {
                    "departmentId": "51",
                    "name": "长沙",
                    "departmentList": []
                },
                {
                    "departmentId": "74",
                    "parentId": "49",
                    "name": "湘潭",
                    "departmentList": []
                }
            ]
        },
        {
            "departmentId": "2",
            "name": "北京市",
            "departmentList": [
                {
                    "departmentId": "5",
                    "name": "海淀",
                    "departmentList": []
                },
                {
                    "departmentId": "4",
                    "name": "朝阳",
                    "departmentList": []
                },
                {
                    "departmentId": "12",
                    "name": "通州",
                    "departmentList": []
                }
            ]
        },
        {
            "departmentId": "11",
            "name": "重庆",
            "departmentList": []
        },
        {
            "departmentId": "3",
            "name": "黑龙江",
            "departmentList": [
                {
                    "departmentId": "7",
                    "name": "哈尔滨",
                    "departmentList": []
                }
            ]
        }
    ]
}]


// 将上面的数据每一个数组元素添加一个strName字段，对应值是  ‘国/省/市/县’格式
connectName(arr, str=''){
  arr.map((item) => {
    item.strName = `${str}${item.name}`
    if(item.departmentList.length){
      const addstr = `${item.strName}/`
      this.connectName(item.departmentList, addstr)
    }
  })
  return arr
},
// 调用
connectName(jsonArr)


// 每一级的对象会包含strName字段,  如第一阶梯会有strName:"中国/湖南/娄底/双峰"
console.log(connectName(jsonArr))