How to convert Map to array of object?

user_8423761 0
Viewed 95996

i'm trying to convert a Map into array of object

Lets say I have the following map:

let myMap = new Map().set('a', 1).set('b', 2);

And I want to convert the above map into the following:

[
   {
      "name": "a",
      "value": "1",
   },
   {
      "name": "b",
      "value": "2",
   }
]
arrays javascript
6 Answers

You could take Array.from and map the key/value pairs.

let map = new Map().set('a', 1).set('b', 2),
    array = Array.from(map, ([name, value]) => ({ name, value }));

console.log(array);

user_14476750

Use Spread syntax and Array.map():

let myMap = new Map().set('a', 1).set('b', 2);

const arr = [...myMap].map(([name, value]) => ({ name, value }));

console.log(arr);

user_111297510

with spread of ES6 like this:

let myMap = new Map().set('a', 1).set('b', 2);

const  result = Array.from(myMap).map(([name, value]) => ({name, value}))

console.log(result);

user_112708400

You can also simply iterate over the Map object using any compatible iteration method and add each item as an object to the resulting array.

For example, you can use Map.prototype.forEach() in the following way:

const myMap = new Map().set('a', 1).set('b', 2);
const arr = [];

myMap.forEach((value, name) => arr.push({ name, value }));

console.log(arr);

Or, as an alternative, you may use the for...of loop like so:

const myMap = new Map().set('a', 1).set('b', 2);
const arr = [];

for (const [name, value] of myMap) {
    arr.push({ name, value });
}

console.log(arr);

Wrote a blog post explaining different methods for those who're interested in learning more.

user_23822830

Very simple I will explain in steps:

  1. Spread a map into an array of arrays.
const map = new Map().set('a', 1).set('b', 2).set('c', 3)
const mapArr = [...map] // array of arrays
  1. Map each subarray as key-value pairs. map function returns a new array containing object of key-value pairs.
const arr = mapArr.map(([key, value]) => ({key, value}))

** Remember: ** the name we use for mapping the data will be the name of the object mapped in this case key and value.

One liner:

const map = new Map().set('a', 1).set('b', 2).set('c', 3)
const arr = [...map ].map(([key, value]) => ({key, value}))
console.log({arr})

user_53720080

With ES6 Spread syntax only :

const myMap = new Map().set('a', 1).set('b', 2);
const arr = [...myMap];
console.log(arr);
user_72169830
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