Transform nested array of objects to an object

Question

I am trying to convert a nested array to an object, I made several attempts but without success.

these are the data i have

[
  ['key1', { childKey1: "text" }, { childKey2: "text" }],
  ['key2', { childKey1: "text" }, { childKey2: "text" }]
]

this is the data i need

{
  key1: {
    childKey1: "text",
    childKey2: "text"
  },
  key2: {
    childKey1: "text",
    childKey2: "text"
  }
}

This is not JSON. [What is the difference between JSON and Object Literal Notation?](https://stackoverflow.com/q/2904131/1218980) — Emile Bergeron, Jan 10 '20 at 19:17
Does this answer your question? [Convert Array to Object](https://stackoverflow.com/questions/4215737/convert-array-to-object) — Heretic Monkey, Jan 10 '20 at 19:18

Ori Drori · Accepted Answer · 2020-01-10T17:54:44.810

Map the data to entries - [[key, value], [key, value]]. Use destructuring to get the key (the 1st item in a sub-array), and rest syntax to get an array of objects. Merge the array of objects by spreading the array of objects into Object.assign() to get the value. Use Object.fromEntries() to convert the entries to an object.

const data = [['key1', {childKey1: "text"}, {childKey2: "text"}], ['key2', {childKey1: "text"}, {childKey2: "text"}]]

const result = Object.fromEntries(data.map(
  ([k, ...v]) => [k, Object.assign({}, ...v)]
))

console.log(result)

Michalis Garganourakis · Answer 2 · 2020-01-10T18:09:35.733

.reduce() method is another way to approach this.

const arr = [['key1', {childKey1: "text"}, {childKey2: "text"}], ['key2', {childKey1: "text"}, {childKey2: "text"}]];

const newArr = arr.reduce((accumulator, currVal) => {
  const [key, ...values] = currVal; // destruct array and separate key from all other values
  
  accumulator[key] = Object.assign({}, ...values); // assign values to your final object, using the key extracted above
  
  return accumulator;
}, {});

console.log(newArr);

score 1 · Answer 3 · answered Jan 10 '20 at 17:58

You may try reduce to achieve such task. You could do something like this:

    const data = [
      ["key1", { childKey1: "text" }, { childKey2: "text" }],
      ["key2", { childKey1: "text" }, { childKey2: "text" }]
    ];
    
    function dataToJSON(data) {
      return data.reduce((acc, current) => {
        const [key, ...values] = current;
        acc[key] = Object.assign({}, ...values);
        return acc;
      }, {});
    }

    console.log(dataToJSON(data));

Works perfect for any number of children. You have to be careful with repeated keys not to overwrite a previous one.

score 0 · Answer 4 · answered Jan 10 '20 at 18:09

I know this was already answered, but here's my attempt at it:

let jsonArray = [['key1', {childKey1: "text"}, {childKey2: "text"}], ['key2', {childKey1: "text"}, {childKey2: "text"}]];
let newJson  = {};

for(var i=0; i<jsonArray.length; i++){
 newJson[jsonArray[i][0]] = Object.assign({}, ...jsonArray[i].slice(1));
}

console.log(newJson);

Transform nested array of objects to an object

4 Answers4