Transform objects to array using lodash

Question

I would like to transform an object to an array format. The input object is

{
  "index": {
    "0": 40,
    "1": 242
  },
  "TID": {
    "0": "11",
    "1": "22"
  },
  "DepartureCity": {
    "0": "MCI",
    "1": "CVG"
  },
  "ArrivalCity": {
    "0": "SFB",
    "1": "LAS"
  },
  "Price": {
    "0": 90,
    "1": 98
  }
}

And the expected output is

[
  {
    "index": 40,
    "TID": "11",
    "DepartureCity": "MCI",
    "ArrivalCity": "SFB",
    "Price": 90
  },
  {
    "index": 242,
    "TID": "22",
    "DepartureCity": "CVG",
    "ArrivalCity": "LAS",
    "Price": 98
  }
]

I tried using for loops, but it is getting more complicated. If any one can help me, it would be really thankful.

Dose none of the answers fulfills what you need? or exactly what you are looking for! we may able to still help! (and that will help the community too) — Koushik Chatterjee, Sep 15 '18 at 16:07

score 4 · Answer 1 · answered Aug 20 '18 at 11:13

Here is a lodash approach

_.merge([], ..._.map(obj, (v, k) => _.mapValues(v, ev=> ({[k]:ev}))))

let inputObj = {
  "index": {
    "0": 40,
    "1": 242
  },
  "TID": {
    "0": "11",
    "1": "22"
  },
  "DepartureCity": {
    "0": "MCI",
    "1": "CVG"
  },
  "ArrivalCity": {
    "0": "SFB",
    "1": "LAS"
  },
  "Price": {
    "0": 90,
    "1": 98
  }
};

let res = _.merge([], ..._.map(inputObj, (v, k) => _.mapValues(v, ev=> ({[k] :ev}))));

console.log(res);

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.10/lodash.min.js"></script>

CertainPerformance · Answer 2 · 2018-08-20T09:13:38.777

Try reduce-ing the entries into an array of objects, iterating over each value of the inner objects:

const input={"index":{"0":40,"1":242},"TID":{"0":"11","1":"22"},"DepartureCity":{"0":"MCI","1":"CVG"},"ArrivalCity":{"0":"SFB","1":"LAS"},"Price":{"0":90,"1":98}}

const output = Object.entries(input).reduce((a, [key, obj]) => {
  Object.values(obj).forEach((val, i) => {
    if (!a[i]) a[i] = {};
    a[i][key] = val;
  });
  return a;
}, []);
console.log(output);

score 1 · Answer 3 · answered Aug 20 '18 at 09:14

You can use Object.keys in combination with reduce

let object = { "index": { "0": 40, "1": 242 }, "TID": { "0": "11", "1": "22" }, "DepartureCity": { "0": "MCI", "1": "CVG" }, "ArrivalCity": { "0": "SFB", "1": "LAS" }, "Price": { "0": 90, "1": 98 } }

result = Object.keys(object['index']).map(function(key){
  return Object.keys(object).reduce(function(obj, item){
    obj[item] = object[item][key];
    return obj;
  }, {});
});
console.log(result);

score 0 · Answer 4 · answered Aug 20 '18 at 09:23

You could map the inner values to the according index.

var data = { index: { 0: 40, 1: 242 }, TID: { 0: "11", 1: "22" }, DepartureCity: { 0: "MCI", 1: "CVG" }, ArrivalCity: { 0: "SFB", 1: "LAS" }, Price: { 0: 90, 1: 98 } },
    result = Object
        .entries(data)
        .reduce(
            (r, [k, o]) => Object
                .entries(o)
                .map(([i, v]) => Object.assign(r[i] || {}, { [k]: v })),
            []
        );

console.log(result);

.as-console-wrapper { max-height: 100% !important; top: 0; }

score 0 · Answer 5 · answered Aug 20 '18 at 09:33

With lodash you just need to use _.reduce() and _.forEach() methods, like this:

const result = _.reduce(Object.entries(object), function(a, [key, obj]){
  _.forEach(Object.values(obj), function(val, i){
    if (!a[i]) a[i] = {};
    a[i][key] = val;
  });
  return a;
}, []);

Demo:

const object = {
  "index": {
    "0": 40,
    "1": 242
  },
  "TID": {
    "0": "11",
    "1": "22"
  },
  "DepartureCity": {
    "0": "MCI",
    "1": "CVG"
  },
  "ArrivalCity": {
    "0": "SFB",
    "1": "LAS"
  },
  "Price": {
    "0": 90,
    "1": 98
  }
};

const result = _.reduce(Object.entries(object), function(a, [key, obj]){
  _.forEach(Object.values(obj), function(val, i){
    if (!a[i]) a[i] = {};
    a[i][key] = val;
  });
  return a;
}, []);

console.log(result);

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.10/lodash.core.js"></script>

Transform objects to array using lodash

5 Answers5