array.prototype.reduce

array.prototype.reduce

An ES5 spec-compliant Array.prototype.reduce 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 spec.

Because Array.prototype.reduce depends on a receiver (the “this” value), the main export takes the array to operate on as the first argument.

Example

var reduce = require('array.prototype.reduce');
var assert = require('assert');

assert.equal(reduce([1, 2, 3], function (prev, x) { return prev + x; }), 6);
assert.equal(reduce([1, 2, 3], function (prev, x) { return prev + x; }, 1), 7);

var reduce = require('array.prototype.reduce');
var assert = require('assert');
/* when Array#reduce is not present */
delete Array.prototype.reduce;
var shimmed = reduce.shim();
assert.equal(shimmed, reduce.getPolyfill());
var arr = [1, 2, 3];
var sum = function (a, b) { return a + b; };
assert.equal(arr.reduce(sum), reduce(arr, sum));
assert.equal(arr.reduce(sum), 6);
assert.equal(arr.reduce(sum, 1), 7);

var reduce = require('array.prototype.reduce');
var assert = require('assert');
/* when Array#reduce is present */
var shimmed = reduce.shim();
assert.equal(shimmed, Array.prototype.reduce);
assert.equal(arr.reduce(sum), reduce(arr, sum));

Tests

Simply clone the repo, npm install, and run npm test

Changelog

v1.0.8 - 2025-03-14

Commits

• [actions] split out node 10-20, and 20+ 14cb785
• [Dev Deps] update @es-shims/api, @ljharb/eslint-config, auto-changelog, has-strict-mode, tape 1d3d206
• [Deps] update call-bind, es-abstract, es-object-atoms, is-string 18f0dcc
• [Refactor] use call-bound directly f64c7db
• [Tests] replace aud with npm audit c79219f
• [Dev Deps] add missing peer dep baae754