Transform array of objects to another array of objects

Question

i am currently struggling to transform an array of objects to fit my needs.

My initial array is looking like this:

 [{
    "adId": "uuid"
    "carBrand": "audi",
    "carColor: "blue",
    "carType": "sedan"
    "yearOfProduction": 1999,
    "price": 10.000
  },{
    "adId": "uuid"
    "carBrand": "mercedes",
    "carColor: "yellow",
    "carType": "coupe"
    "yearOfProduction": 2004,
    "price": 14.000
  },{
    "adId": "uuid"
    "carBrand": "bmw",
    "carColor: "green",
    "carType": "minivan"
    "yearOfProduction": 2007,
    "price": 6.000
 }]

I would like that my new array look like this:

[{
    "adId": "uuid"
    "carBrand": "audi",
    "carColor: "blue"
},{
    "adId": "uuid"
    "carBrand": "audi",
    "carType: "sedan"
},{
    "adId": "uuid"
    "carBrand": "audi",
    "yearOfProduction: "1999"
},{
    "adId": "uuid"
    "carBrand": "audi",
    "price: 10.000
},
{
    "adId": "uuid"
    "carBrand": "mercedes",
    "carColor: "yellow"
},{
    "adId": "uuid"
    "carBrand": "mercedes",
    "carType: "coupe"
},{
    "adId": "uuid"
    "carBrand": "mercedes",
    "yearOfProduction: "2004"
},{
    "adId": "uuid"
    "carBrand": "mercedes",
    "price: 14.000
},
    {
    "adId": "uuid"
    "carBrand": "bmw",
    "carColor: "green"
},{
    "adId": "uuid"
    "carBrand": "bmw",
    "carType": "minivan"
},{
    "adId": "uuid"
    "carBrand": "bmw",
    "yearOfProduction": 2007,
},{
    "adId": "uuid"
    "carBrand": "bmw",
    "price": 6.000
}]

So basically "adId" and "carBrand" properties would be present on every new object together with each one of the properties that is left. I've tried various scenarios with lodash but i simply can't make it. Any suggestions and hints are welcome, cheers.

Answer 1

You can easily achieve the result using flatMap and Object.entries

One-liner

arr.flatMap(({ adId, carBrand, ...rest }) => Object.entries(rest).map(([k, v]) => ({ adId, carBrand, [k]: v })))

const arr = [
  {
    adId: "uuid",
    carBrand: "audi",
    carColor: "blue",
    carType: "sedan",
    yearOfProduction: 1999,
    price: 10.0,
  },
  {
    adId: "uuid",
    carBrand: "mercedes",
    carColor: "yellow",
    carType: "coupe",
    yearOfProduction: 2004,
    price: 14.0,
  },
  {
    adId: "uuid",
    carBrand: "bmw",
    carColor: "green",
    carType: "minivan",
    yearOfProduction: 2007,
    price: 6.0,
  },
];

const result = arr.flatMap(({ adId, carBrand, ...rest }) => {
  return Object.entries(rest).map(([k, v]) => ({ adId, carBrand, [k]: v }));
});

console.log(result);