array.prototype.splice/README.md

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

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

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An ES spec-compliant `Array.prototype.splice` 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://tc39.es/ecma262/#sec-array.prototype.splice).

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

## Engines where this is needed

Note: this list is not exhaustive.

  - IE 8 and below, and pre-ES6 engines: `deleteCount` isn't defaulted to `length - start` until ES6
  - Safari 5.0: sometimes it returns `undefined`
  - Safari 7/8: sparse arrays of size 1e5 or greater break
  - Opera 12.15: breaks on small sparse arrays

## Example

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

var a = [1, 1, 1];
assert.deepEqual(splice(a, 1, 2), [1, 1]);
assert.deepEqual(a, [1]);
```

```js
var splice = require('array.prototype.splice');
var assert = require('assert');
/* when Array#splice is not present */
delete Array.prototype.splice;
var shimmed = splice.shim();
assert.equal(shimmed, splice.getPolyfill());
assert.equal(shimmed, Array.prototype.splice);
assert.deepEqual([1, 2, 3].splice(1, 2, 3), splice([1, 2, 3], 1, 2, 3));
```

```js
var splice = require('array.prototype.splice');
var assert = require('assert');
/* when Array#splice is present */
var shimmed = splice.shim();
assert.equal(shimmed, Array.prototype.splice);
assert.deepEqual([1, 2, 3].splice(1, 2, 3), splice([1, 2, 3], 1, 2, 3));
```

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

[package-url]: https://npmjs.org/package/array.prototype.splice
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[license-url]: LICENSE
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