Object.fromEntries
Creates an object from a list of key–value pairs.
Available since: ES2019
Syntax
Object.fromEntries(entries)Parameters
| Parameter | Type | Description |
|---|---|---|
| entries | Iterable | An array of [key, value] pairs, or a Map. |
Return value
objectA new object made from the pairs.
Examples
Pairs become an object:
const pairs = [['name', 'Anna'], ['city', 'Berlin']];
console.log(Object.fromEntries(pairs));Output:
{
"name": "Anna",
"city": "Berlin"
}Transforming object values through entries and fromEntries:
const prices = { tea: 3, coffee: 5 };
const doubled = Object.fromEntries(
Object.entries(prices).map(([key, value]) => [key, value * 2]),
);
console.log(doubled);Output:
{
"tea": 6,
"coffee": 10
}A Map into a plain object:
const map = new Map([['a', 1], ['b', 2]]);
console.log(Object.fromEntries(map));Output:
{
"a": 1,
"b": 2
}Notes
Together Object.entries() and Object.fromEntries() let you apply array methods to objects: map(), filter(), sort().
See also
- Object.entries — Returns an array of property name and value pairs.
- Map — A collection of key–value pairs where a key can be anything.
- Array.prototype.map — Creates a new array by transforming every element.
Related recipes
In the tutorial
- Iterating objects and Object functions — How to iterate over an object in JavaScript: Object.keys, Object.values, Object.entries, Object.fromEntries, for...in and Object.hasOwn.