README.md (2546B)
1 # is-extendable [](http://badge.fury.io/js/is-extendable) 2 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?" 4 5 ## Install 6 7 Install with [npm](https://www.npmjs.com/) 8 9 ```sh 10 $ npm i is-extendable --save 11 ``` 12 13 ## Usage 14 15 ```js 16 var isExtendable = require('is-extendable'); 17 ``` 18 19 Returns true if the value is any of the following: 20 21 * `array` 22 * `regexp` 23 * `plain object` 24 * `function` 25 * `date` 26 * `error` 27 28 ## Notes 29 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: 31 32 * the value is not a primitive, or 33 * that the object is an `object`, `function` 34 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`. 36 37 ## Related projects 38 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. 45 46 ## Running tests 47 48 Install dev dependencies: 49 50 ```sh 51 $ npm i -d && npm test 52 ``` 53 54 ## Contributing 55 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) 57 58 ## Author 59 60 **Jon Schlinkert** 61 62 + [github/jonschlinkert](https://github.com/jonschlinkert) 63 + [twitter/jonschlinkert](http://twitter.com/jonschlinkert) 64 65 ## License 66 67 Copyright © 2015 Jon Schlinkert 68 Released under the MIT license. 69 70 *** 71 72 _This file was generated by [verb-cli](https://github.com/assemble/verb-cli) on July 04, 2015._