array.prototype.findlast

array.prototype.findlast

An ESnext spec-compliant Array.prototype.findLast 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.findLast 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.findlast

Usage/Examples

var findLast = require('array.prototype.findlast');
var assert = require('assert');

var arr = [1, [2], [], 3, [[4]]];
var isNumber = function (x) { return typeof x === 'number' };

assert.deepEqual(findLast(arr, isNumber), 3);

var findLast = require('array.prototype.findlast');
var assert = require('assert');
/* when Array#findLast is not present */
delete Array.prototype.findLast;
var shimmed = findLast.shim();

assert.equal(shimmed, findLast.getPolyfill());
assert.deepEqual(arr.findLast(isNumber), findLast(arr, isNumber));

var findLast = require('array.prototype.findlast');
var assert = require('assert');
/* when Array#findLast is present */
var shimmed = findLast.shim();

assert.equal(shimmed, Array.prototype.findLast);
assert.deepEqual(arr.findLast(isNumber), findLast(arr, isNumber));

Tests

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

Similar packages

Other packages similar to array.prototype.findlast

lodash.findlast

Lodash is a popular utility library that includes a `findLast` method. This method is similar to array.prototype.findlast in that it searches an array from the end and returns the last element that passes a given test. The main difference is that lodash's `findLast` is a standalone function that takes the array as an argument, rather than being a method on the array prototype.

underscore

Underscore.js is another utility library that offers similar functionality through its `findLast` method. Like lodash, it provides this functionality as a part of a larger set of utilities for working with arrays, objects, and functions. The approach to finding the last element that meets a condition is similar, but underscore does not modify the array prototype.