# class-utils [](https://www.npmjs.com/package/class-utils) [](https://npmjs.org/package/class-utils) [](https://npmjs.org/package/class-utils) [](https://travis-ci.org/jonschlinkert/class-utils)
> Utils for working with JavaScript classes and prototype methods.
Please consider following this project's author, [Jon Schlinkert](https://github.com/jonschlinkert), and consider starring the project to show your :heart: and support.
## Install
Install with [npm](https://www.npmjs.com/):
```sh
$ npm install --save class-utils
```
## Usage
```js
var cu = require('class-utils');
```
## API
### [.has](index.js#L43)
Returns true if an array has any of the given elements, or an object has any of the give keys.
**Params**
* `obj` **{Object}**
* `val` **{String|Array}**
* `returns` **{Boolean}**
**Example**
```js
cu.has(['a', 'b', 'c'], 'c');
//=> true
cu.has(['a', 'b', 'c'], ['c', 'z']);
//=> true
cu.has({a: 'b', c: 'd'}, ['c', 'z']);
//=> true
```
### [.hasAll](index.js#L90)
Returns true if an array or object has all of the given values.
**Params**
* `val` **{Object|Array}**
* `values` **{String|Array}**
* `returns` **{Boolean}**
**Example**
```js
cu.hasAll(['a', 'b', 'c'], 'c');
//=> true
cu.hasAll(['a', 'b', 'c'], ['c', 'z']);
//=> false
cu.hasAll({a: 'b', c: 'd'}, ['c', 'z']);
//=> false
```
### [.arrayify](index.js#L117)
Cast the given value to an array.
**Params**
* `val` **{String|Array}**
* `returns` **{Array}**
**Example**
```js
cu.arrayify('foo');
//=> ['foo']
cu.arrayify(['foo']);
//=> ['foo']
```
### [.hasConstructor](index.js#L152)
Returns true if a value has a `contructor`
**Params**
* `value` **{Object}**
* `returns` **{Boolean}**
**Example**
```js
cu.hasConstructor({});
//=> true
cu.hasConstructor(Object.create(null));
//=> false
```
### [.nativeKeys](index.js#L174)
Get the native `ownPropertyNames` from the constructor of the given `object`. An empty array is returned if the object does not have a constructor.
**Params**
* `obj` **{Object}**: Object that has a `constructor`.
* `returns` **{Array}**: Array of keys.
**Example**
```js
cu.nativeKeys({a: 'b', b: 'c', c: 'd'})
//=> ['a', 'b', 'c']
cu.nativeKeys(function(){})
//=> ['length', 'caller']
```
### [.getDescriptor](index.js#L208)
Returns property descriptor `key` if it's an "own" property of the given object.
**Params**
* `obj` **{Object}**
* `key` **{String}**
* `returns` **{Object}**: Returns descriptor `key`
**Example**
```js
function App() {}
Object.defineProperty(App.prototype, 'count', {
get: function() {
return Object.keys(this).length;
}
});
cu.getDescriptor(App.prototype, 'count');
// returns:
// {
// get: [Function],
// set: undefined,
// enumerable: false,
// configurable: false
// }
```
### [.copyDescriptor](index.js#L238)
Copy a descriptor from one object to another.
**Params**
* `receiver` **{Object}**
* `provider` **{Object}**
* `name` **{String}**
* `returns` **{Object}**
**Example**
```js
function App() {}
Object.defineProperty(App.prototype, 'count', {
get: function() {
return Object.keys(this).length;
}
});
var obj = {};
cu.copyDescriptor(obj, App.prototype, 'count');
```
### [.copy](index.js#L264)
Copy static properties, prototype properties, and descriptors
from one object to another.
**Params**
* `receiver` **{Object}**
* `provider` **{Object}**
* `omit` **{String|Array}**: One or more properties to omit
* `returns` **{Object}**
### [.inherit](index.js#L299)
Inherit the static properties, prototype properties, and descriptors
from of an object.
**Params**
* `receiver` **{Object}**
* `provider` **{Object}**
* `omit` **{String|Array}**: One or more properties to omit
* `returns` **{Object}**
### [.extend](index.js#L343)
Returns a function for extending the static properties, prototype properties, and descriptors from the `Parent` constructor onto `Child` constructors.
**Params**
* `Parent` **{Function}**: Parent ctor
* `extend` **{Function}**: Optional extend function to handle custom extensions. Useful when updating methods that require a specific prototype.
* `Child` **{Function}**: Child ctor
* `proto` **{Object}**: Optionally pass additional prototype properties to inherit.
* `returns` **{Object}**
**Example**
```js
var extend = cu.extend(Parent);
Parent.extend(Child);
// optional methods
Parent.extend(Child, {
foo: function() {},
bar: function() {}
});
```
### [.bubble](index.js#L356)
Bubble up events emitted from static methods on the Parent ctor.
**Params**
* `Parent` **{Object}**
* `events` **{Array}**: Event names to bubble up
## About
Contributing
Pull requests and stars are always welcome. For bugs and feature requests, [please create an issue](../../issues/new).
Running Tests
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:
```sh
$ npm install && npm test
```
Building docs
_(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.)_
To generate the readme, run the following command:
```sh
$ npm install -g verbose/verb#dev verb-generate-readme && verb
```
### Related projects
You might also be interested in these projects:
* [define-property](https://www.npmjs.com/package/define-property): Define a non-enumerable property on an object. Uses Reflect.defineProperty when available, otherwise Object.defineProperty. | [homepage](https://github.com/jonschlinkert/define-property "Define a non-enumerable property on an object. Uses Reflect.defineProperty when available, otherwise Object.defineProperty.")
* [delegate-properties](https://www.npmjs.com/package/delegate-properties): Deep-clone properties from one object to another and make them non-enumerable, or make existing properties… [more](https://github.com/jonschlinkert/delegate-properties) | [homepage](https://github.com/jonschlinkert/delegate-properties "Deep-clone properties from one object to another and make them non-enumerable, or make existing properties on an object non-enumerable.")
* [is-descriptor](https://www.npmjs.com/package/is-descriptor): Returns true if a value has the characteristics of a valid JavaScript descriptor. Works for… [more](https://github.com/jonschlinkert/is-descriptor) | [homepage](https://github.com/jonschlinkert/is-descriptor "Returns true if a value has the characteristics of a valid JavaScript descriptor. Works for data descriptors and accessor descriptors.")
### Contributors
| **Commits** | **Contributor** |
| --- | --- |
| 34 | [jonschlinkert](https://github.com/jonschlinkert) |
| 8 | [doowb](https://github.com/doowb) |
| 2 | [wtgtybhertgeghgtwtg](https://github.com/wtgtybhertgeghgtwtg) |
### Author
**Jon Schlinkert**
* [linkedin/in/jonschlinkert](https://linkedin.com/in/jonschlinkert)
* [github/jonschlinkert](https://github.com/jonschlinkert)
* [twitter/jonschlinkert](https://twitter.com/jonschlinkert)
### License
Copyright © 2018, [Jon Schlinkert](https://github.com/jonschlinkert).
Released under the [MIT License](LICENSE).
***
_This file was generated by [verb-generate-readme](https://github.com/verbose/verb-generate-readme), v0.6.0, on January 11, 2018._