# array.prototype.filter <sup>[![Version Badge][npm-version-svg]][package-url]</sup>

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An ES5 spec-compliant `Array.prototype.filter` shim/polyfill/replacement that works as far down as ES3.

This package implements the [es-shim API](https://github.com/es-shims/api) interface. It works in an ES3-supported environment and complies with the [spec](https://www.ecma-international.org/ecma-262/5.1/).

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

## Example

```js
var filter = require('array.prototype.filter');
var assert = require('assert');

assert.deepEqual(filter([1, 2, 3], function (x) { return x >= 2; }), [2, 3]);
assert.deepEqual(filter([1, 2, 3], function (x) { return x <= 2; }), [1, 2]);
```

```js
var filter = require('array.prototype.filter');
var assert = require('assert');
/* when Array#filter is not present */
delete Array.prototype.filter;
var shimmedFilter = filter.shim();
assert.equal(shimmedFilter, filter.getPolyfill());
var arr = [1, 2, 3];
var isOdd = function (x) { return x % 2 !== 0; };
assert.deepEqual(arr.filter(isOdd), filter(arr, isOdd));
```

```js
var filter = require('array.prototype.filter');
var assert = require('assert');
/* when Array#filter is present */
var shimmedFilter = filter.shim();
assert.equal(shimmedFilter, Array.prototype.filter);
assert.deepEqual(arr.filter(isOdd), filter(arr, isOdd));
```

## Tests
Simply clone the repo, `npm install`, and run `npm test`

[package-url]: https://npmjs.org/package/array.prototype.filter
[npm-version-svg]: https://versionbadg.es/es-shims/Array.prototype.filter.svg
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[dev-deps-url]: https://david-dm.org/es-shims/Array.prototype.filter#info=devDependencies
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[license-url]: LICENSE
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