array.prototype.flat (1.3.3)
Published 2026-02-24 13:53:00 +00:00 by atheaadmin
Installation
registry=npm install array.prototype.flat@1.3.3"array.prototype.flat": "1.3.3"About this package
array.prototype.flat 
An ES2019 spec-compliant Array.prototype.flat shim/polyfill/replacement that works as far down as ES3.
This package implements the es-shim API interface. It works in an ES3-supported environment and complies with the proposed spec.
Because Array.prototype.flat depends on a receiver (the this value), the main export takes the array to operate on as the first argument.
Getting started
npm install --save array.prototype.flat
Usage/Examples
var flat = require('array.prototype.flat');
var assert = require('assert');
var arr = [1, [2], [], 3, [[4]]];
assert.deepEqual(flat(arr, 1), [1, 2, 3, [4]]);
var flat = require('array.prototype.flat');
var assert = require('assert');
/* when Array#flat is not present */
delete Array.prototype.flat;
var shimmedFlat = flat.shim();
assert.equal(shimmedFlat, flat.getPolyfill());
assert.deepEqual(arr.flat(), flat(arr));
var flat = require('array.prototype.flat');
var assert = require('assert');
/* when Array#flat is present */
var shimmedIncludes = flat.shim();
var mapper = function (x) { return [x, 1]; };
assert.equal(shimmedIncludes, Array.prototype.flat);
assert.deepEqual(arr.flat(mapper), flat(arr, mapper));
Tests
Simply clone the repo, npm install, and run npm test
Dependencies
Dependencies
| ID | Version |
|---|---|
| call-bind | ^1.0.8 |
| define-properties | ^1.2.1 |
| es-abstract | ^1.23.5 |
| es-shim-unscopables | ^1.0.2 |
Development Dependencies
| ID | Version |
|---|---|
| @es-shims/api | ^2.5.1 |
| @ljharb/eslint-config | ^21.1.1 |
| auto-changelog | ^2.5.0 |
| covert | ^1.1.1 |
| encoding | ^0.1.13 |
| eslint | =8.8.0 |
| evalmd | ^0.0.19 |
| function-bind | ^1.1.2 |
| has-strict-mode | ^1.0.1 |
| in-publish | ^2.0.1 |
| npmignore | ^0.3.1 |
| nyc | ^10.3.2 |
| object-inspect | ^1.13.3 |
| safe-publish-latest | ^2.0.0 |
| tape | ^5.9.0 |
Keywords
Array.prototype.flatten
Array.prototype.flat
flatten
flat
array
ESnext
shim
polyfill
flatMap
Array.prototype.flatMap
es-shim API