javascript - How to loop through multidimensional array and map field to key -

i have object structured this:

[   {     "id": 34,     "parent": 0,     "title": "level 1 a",     "children": []   },   {     "id": 35,     "parent": 0,     "title": "level 1 b",     "children": [       {         "id": 36,         "parent": 35,         "title": "level 2 a",         "children": [           {             "id": 37,             "parent": 36,             "title": "level 3 a",             "children": []           },           {             "id": 38,             "parent": 36,             "title": "level 3 b",             "children": []           }         ]       }     ]   } ] 

and i'm trying loop through , make "title" key end this:

[   {     "level 1 a": {       "id": 34,       "parent": 0,       "title": "level 1 a",       "children": []     }   },   {     "level 1 b": {       "id": 35,       "parent": 0,       "title": "level 1 b",       "children": [         {           "level 2 a": {             "id": 36,             "parent": 35,             "title": "level 2 a",             "children": [               {                 "level 3 a": {                   "id": 37,                   "parent": 36,                   "title": "level 3 a",                   "children": []                 }                },               {                 "level 3 b": {                   "id": 38,                   "parent": 36,                   "title": "level 3 b",                   "children": []                 }               }             ]           }          }       ]     }   } ] 

i tried this, doesn't go through children arrays level 1 elements updated:

    (var = 0, l = response.length; < l; i++) {         map[response[i].title] = response[i];     } 

i believe need use recursion, i'm having trouble figuring out how done javascript. in advance suggestions.

you need update code following

function updatearray(arr) {     var updatedresponse = [];     (var = 0, l = arr.length; < l; i++) {         var obj = {};         if(arr[i].children !== undefined) {             arr[i].children = updatearray(arr[i].children);         }         obj[arr[i].title] = arr[i];         updatedresponse.push(obj);   }   return updatedresponse; }  var updatedarray = updatearray(response); 

for reference - http://plnkr.co/edit/bxlol9vhxuxzolzkhbte?p=preview