OBJECT.FROMENTRIES()

ECMAScript 2019 added a static method fromEntries() to the Object class which builds an object from a collection of key-value array pairs. This method performs the opposite operation of Object.entries(). This method is demonstrated here:

const obj = {
 foo: 'bar',
 baz: 'qux'
};

const objEntries = Object.entries(obj);

console.log(objEntries);
// [["foo", "bar"], ["baz", "qux"]]

console.log(Object.fromEntries(objEntries));
// { foo: "bar", baz: "qux" }

The static method expects an iterable object containing any number of iterable objects of size 2. This is especially useful in cases where you wish to convert a Map instance to an Object instance, as the Map iterator's output exactly matches the signature that fromEntries() ingests:

const map = new Map().set('foo', 'bar');

console.log(Object.fromEntries(map));
// { foo: "bar" }