lodash.flatmap

What is lodash.flatmap?

The lodash.flatmap package is a utility library that provides a method to map and flatten a collection in a single operation. It is part of the Lodash library, which is a popular JavaScript utility library that offers a wide range of functions for common programming tasks.

What are lodash.flatmap's main functionalities?

Map and Flatten

This feature allows you to map each element in a collection to a new value and then flatten the result into a single array. In this example, we map each user to their pets and then flatten the resulting arrays into a single array of pet names.

const _ = require('lodash.flatmap');
const users = [
  { 'user': 'barney', 'age': 36, 'pets': ['hoppy'] },
  { 'user': 'fred', 'age': 40, 'pets': ['baby puss', 'dino'] }
];
const result = _.flatMap(users, function(o) { return o.pets; });
console.log(result); // ['hoppy', 'baby puss', 'dino']

Other packages similar to lodash.flatmap

ramda

Ramda is a functional programming library for JavaScript that provides a similar flatMap function called R.chain. It is designed to work with immutable data and provides a more functional approach compared to lodash.flatmap.

underscore

Underscore is another popular utility library for JavaScript that offers a similar function called _.flatten. While it does not combine mapping and flattening in a single function, it provides similar functionality through separate map and flatten methods.

array.prototype.flatmap

This package is a polyfill for the Array.prototype.flatMap method, which is a standard method in modern JavaScript. It provides similar functionality to lodash.flatmap but is designed to work as a native method on arrays.

README

lodash.flatmap v4.5.0

The lodash method _.flatMap exported as a Node.js module.

Installation

Using npm:

$ {sudo -H} npm i -g npm
$ npm i --save lodash.flatmap

In Node.js:

var flatMap = require('lodash.flatmap');

See the documentation or package source for more details.