1 # is-extendable [![NPM version](https://badge.fury.io/js/is-extendable.svg)](http://badge.fury.io/js/is-extendable)
3 > Returns true if a value is any of the object types: array, regexp, plain object, function or date. This is useful for determining if a value can be extended, e.g. "can the value have keys?"
7 Install with [npm](https://www.npmjs.com/)
10 $ npm i is-extendable --save
16 var isExtendable = require('is-extendable');
19 Returns true if the value is any of the following:
30 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:
32 * the value is not a primitive, or
33 * that the object is an `object`, `function`
35 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`.
39 * [assign-deep](https://github.com/jonschlinkert/assign-deep): Deeply assign the enumerable properties of source objects to a destination object.
40 * [extend-shallow](https://github.com/jonschlinkert/extend-shallow): Extend an object with the properties of additional objects. node.js/javascript util.
41 * [isobject](https://github.com/jonschlinkert/isobject): Returns true if the value is an object and not an array or null.
42 * [is-plain-object](https://github.com/jonschlinkert/is-plain-object): Returns true if an object was created by the `Object` constructor.
43 * [is-equal-shallow](https://github.com/jonschlinkert/is-equal-shallow): Does a shallow comparison of two objects, returning false if the keys or values differ.
44 * [kind-of](https://github.com/jonschlinkert/kind-of): Get the native type of a value.
48 Install dev dependencies:
51 $ npm i -d && npm test
56 Pull requests and stars are always welcome. For bugs and feature requests, [please create an issue](https://github.com/jonschlinkert/is-extendable/issues/new)
62 + [github/jonschlinkert](https://github.com/jonschlinkert)
63 + [twitter/jonschlinkert](http://twitter.com/jonschlinkert)
67 Copyright © 2015 Jon Schlinkert
68 Released under the MIT license.
72 _This file was generated by [verb-cli](https://github.com/assemble/verb-cli) on July 04, 2015._