3.3 KiB
3.3 KiB
array-includes
An ES7/ES2016 spec-compliant Array.prototype.includes
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.includes
depends on a receiver (the this
value), the main export takes the array to operate on as the first argument.
Engines that need this package include:
- IE (all versions)
- Safari < 9
- Firefox < 43, and 99+
- Chrome < 47
- Edge < 14
- node < 6
Getting started
npm install --save array-includes
Usage
Basic usage: includes(array, value[, fromIndex=0])
var includes = require('array-includes');
var assert = require('assert');
var arr = [ 'one', 'two' ];
includes(arr, 'one'); // true
includes(arr, 'three'); // false
includes(arr, 'one', 1); // false
Example
var arr = [
1,
'foo',
NaN,
-0
];
assert.equal(arr.indexOf(0) > -1, true);
assert.equal(arr.indexOf(-0) > -1, true);
assert.equal(includes(arr, 0), true);
assert.equal(includes(arr, -0), true);
assert.equal(arr.indexOf(NaN) > -1, false);
assert.equal(includes(arr, NaN), true);
assert.equal(includes(arr, 'foo', 0), true);
assert.equal(includes(arr, 'foo', 1), true);
assert.equal(includes(arr, 'foo', 2), false);
/* when Array#includes is not present */
delete Array.prototype.includes;
var shimmedIncludes = includes.shim();
assert.equal(shimmedIncludes, includes.getPolyfill());
assert.equal(arr.includes('foo', 1), includes(arr, 'foo', 1));
/* when Array#includes is present */
var shimmedIncludes = includes.shim();
assert.equal(shimmedIncludes, Array.prototype.includes);
assert.equal(arr.includes(1, 'foo'), includes(arr, 1, 'foo'));
Tests
Simply clone the repo, npm install
, and run npm test