Get last deepest level item in object

Question

I have data and function like this:

const lodash = require('lodash')

var data = [
  {
    "nextStep": [
      {
        "nextStep": [
          {
            "nextStep": [
              {
                "nextStep": [],
                "student": {
                  "name": "Alice",
                  "grade": 1
                }
              }
            ],
            "student": {
              "name": "Lisa",
              "grade": 2
            }
          }
        ],
        "student": {
          "grade": 3,
          "name": "This is GS"
        }
      }
    ],
    "student": {
      "grade": 4,
      "name": "Paul"
    }
  }
]


function searchByJsonPath(path, obj, target) {
  for (var k in obj) {
      if (obj.hasOwnProperty(k))
          if (k === target)
              return path;
          else if (typeof obj[k] === "object") {
              var result = searchByJsonPath(path + "." + k, obj[k], target);
              if (result)
                  return result;
          }
  }
  return false;
}

I want to get the last item in object, the result should be

  "name": "Alice",
  "grade": 1

So I call the searchByJsonPath to get the path and use the lodash to get an item

test = searchByJsonPath('data', data, 'name');

but test = data.0.nextStep.0.nextStep.0.nextStep.0.student

the correct path should be data[0].nextStep[0].nextStep[0].nextStep[0].student

Please advice me.

Answer 1

You can try recursion like below to get the deepest element

var data = [{  "nextStep": [    {      "nextStep": [        {          "nextStep": [            {              "nextStep": [],              "student": {                "name": "Alice",                "grade": 1              }            }          ],          "student": {            "name": "Lisa",            "grade": 2          }        }      ],      "student": {        "grade": 3,        "name": "This is GS"      }    }  ],  "student": {    "grade": 4,    "name": "Paul"  }}]

function getData(obj) {
  return obj.nextStep.length > 0
    ? getData(obj.nextStep[0])
    : obj.student
}

console.log(getData(data[0]))