| # is-extendable [](https://www.npmjs.com/package/is-extendable) [](https://npmjs.org/package/is-extendable) [](https://npmjs.org/package/is-extendable) [](https://travis-ci.org/jonschlinkert/is-extendable) |
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| > Returns true if a value is a plain object, array or function. |
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| ## Install |
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| Install with [npm](https://www.npmjs.com/): |
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| ```sh |
| $ npm install --save is-extendable |
| ``` |
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| ## Usage |
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| ```js |
| var isExtendable = require('is-extendable'); |
| ``` |
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| Returns true if the value is any of the following: |
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| * array |
| * plain object |
| * function |
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| ## Notes |
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| All objects in JavaScript can have keys, but it's a pain to check for this, since we ether need to verify that the value is not `null` or `undefined` and: |
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| * the value is not a primitive, or |
| * that the object is a plain object, function or array |
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| Also note that an `extendable` object is not the same as an [extensible object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/isExtensible), which is one that (in es6) is not sealed, frozen, or marked as non-extensible using `preventExtensions`. |
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| ## Release history |
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| ### v1.0.0 - 2017/07/20 |
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| **Breaking changes** |
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| * No longer considers date, regex or error objects to be extendable |
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| ## About |
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| ### Related projects |
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| * [assign-deep](https://www.npmjs.com/package/assign-deep): Deeply assign the enumerable properties and/or es6 Symbol properies of source objects to the target… [more](https://github.com/jonschlinkert/assign-deep) | [homepage](https://github.com/jonschlinkert/assign-deep "Deeply assign the enumerable properties and/or es6 Symbol properies of source objects to the target (first) object.") |
| * [is-equal-shallow](https://www.npmjs.com/package/is-equal-shallow): Does a shallow comparison of two objects, returning false if the keys or values differ. | [homepage](https://github.com/jonschlinkert/is-equal-shallow "Does a shallow comparison of two objects, returning false if the keys or values differ.") |
| * [is-plain-object](https://www.npmjs.com/package/is-plain-object): Returns true if an object was created by the `Object` constructor. | [homepage](https://github.com/jonschlinkert/is-plain-object "Returns true if an object was created by the `Object` constructor.") |
| * [isobject](https://www.npmjs.com/package/isobject): Returns true if the value is an object and not an array or null. | [homepage](https://github.com/jonschlinkert/isobject "Returns true if the value is an object and not an array or null.") |
| * [kind-of](https://www.npmjs.com/package/kind-of): Get the native type of a value. | [homepage](https://github.com/jonschlinkert/kind-of "Get the native type of a value.") |
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| ### Contributing |
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| Pull requests and stars are always welcome. For bugs and feature requests, [please create an issue](../../issues/new). |
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| ### Building docs |
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| _(This project's readme.md is generated by [verb](https://github.com/verbose/verb-generate-readme), please don't edit the readme directly. Any changes to the readme must be made in the [.verb.md](.verb.md) readme template.)_ |
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| To generate the readme, run the following command: |
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| ```sh |
| $ npm install -g verbose/verb#dev verb-generate-readme && verb |
| ``` |
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| ### Running tests |
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| Running and reviewing unit tests is a great way to get familiarized with a library and its API. You can install dependencies and run tests with the following command: |
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| ```sh |
| $ npm install && npm test |
| ``` |
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| ### Author |
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| **Jon Schlinkert** |
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| * [github/jonschlinkert](https://github.com/jonschlinkert) |
| * [twitter/jonschlinkert](https://twitter.com/jonschlinkert) |
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| ### License |
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| Copyright © 2017, [Jon Schlinkert](https://github.com/jonschlinkert). |
| Released under the [MIT License](LICENSE). |
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| *** |
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| _This file was generated by [verb-generate-readme](https://github.com/verbose/verb-generate-readme), v0.6.0, on July 20, 2017._ |
