array.prototype.findlastindex (original) (raw)

array.prototype.findlastindex Version Badge

github actions coverage dependency status dev dependency status License Downloads

npm badge

An ESnext spec-compliant Array.prototype.findLastIndex 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.findLastIndex 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.findlastindex

Usage/Examples

var findLastIndex = require('array.prototype.findlastindex'); var assert = require('assert');

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

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

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

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

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

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

Tests

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