Web/JavaScript/Reference/Global objects/Object/fromEntries

The Object.fromEntries() method transforms a list of key-value pairs into an object.

Syntax

Object.fromEntries(iterable);

Parameters

iterable: An iterable such as Array or Map or other objects implementing the iterable protocol.

Return value

A new object whose properties are given by the entries of the iterable.

Description

The Object.fromEntries() method takes a list of key-value pairs and returns a new object whose properties are given by those entries. The iterable argument is expected to be an object that implements an @@iterator method, that returns an iterator object, that produces a two element array-like object, whose first element is a value that will be used as a property key, and whose second element is the value to associate with that property key.

Object.fromEntries() performs the reverse of Object.entries().

Examples

Converting a Map to an Object

With Object.fromEntries, you can convert from Map to Object:

const map = new Map([ ['foo', 'bar'], ['baz', 42] ]);
const obj = Object.fromEntries(map);
console.log(obj); // { foo: "bar", baz: 42 }

Converting an Array to an Object

With Object.fromEntries, you can convert from Array to Object:

const arr = [ ['0', 'a'], ['1', 'b'], ['2', 'c'] ];
const obj = Object.fromEntries(arr);
console.log(obj); // { 0: "a", 1: "b", 2: "c" }

Object transformations

With Object.fromEntries, its reverse method Object.entries(), and array manipulation methods, you are able to transform objects like this:

const object1 = { a: 1, b: 2, c: 3 };

const object2 = Object.fromEntries(
  Object.entries(object1)
  .map(([ key, val ]) => [ key, val * 2 ])
);

console.log(object2);
// { a: 2, b: 4, c: 6 }

Specifications

Specification
ECMAScript (ECMA-262)The definition of 'Object.fromEntries' in that specification.

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile						Server
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet	Node.js
`fromEntries`	Chrome Full support 73	Edge Full support 79	Firefox Full support 63	IE No support No	Opera Full support 60	Safari Full support 12.1	WebView Android Full support 73	Chrome Android Full support 73	Firefox Android Full support 63	Opera Android No support No	Safari iOS Full support 12.2	Samsung Internet Android No support No	nodejs Full support 12.0.0

Legend

Full support: Full support
No support: No support