# is-number [![NPM version](https://img.shields.io/npm/v/is-number.svg?style=flat)](https://www.npmjs.com/package/is-number) [![NPM downloads](https://img.shields.io/npm/dm/is-number.svg?style=flat)](https://npmjs.org/package/is-number) [![Build Status](https://img.shields.io/travis/jonschlinkert/is-number.svg?style=flat)](https://travis-ci.org/jonschlinkert/is-number) > Returns true if the value is a number. comprehensive tests. ## Install Install with [npm](https://www.npmjs.com/): ```sh $ npm install --save is-number ``` ## Usage To understand some of the rationale behind the decisions made in this library (and to learn about some oddities of number evaluation in JavaScript), [see this gist](https://gist.github.com/jonschlinkert/e30c70c713da325d0e81). ```js var isNumber = require('is-number'); ``` ### true See the [tests](./test.js) for more examples. ```js isNumber(5e3) //=> 'true' isNumber(0xff) //=> 'true' isNumber(-1.1) //=> 'true' isNumber(0) //=> 'true' isNumber(1) //=> 'true' isNumber(1.1) //=> 'true' isNumber(10) //=> 'true' isNumber(10.10) //=> 'true' isNumber(100) //=> 'true' isNumber('-1.1') //=> 'true' isNumber('0') //=> 'true' isNumber('012') //=> 'true' isNumber('0xff') //=> 'true' isNumber('1') //=> 'true' isNumber('1.1') //=> 'true' isNumber('10') //=> 'true' isNumber('10.10') //=> 'true' isNumber('100') //=> 'true' isNumber('5e3') //=> 'true' isNumber(parseInt('012')) //=> 'true' isNumber(parseFloat('012')) //=> 'true' ``` ### False See the [tests](./test.js) for more examples. ```js isNumber('foo') //=> 'false' isNumber([1]) //=> 'false' isNumber([]) //=> 'false' isNumber(function () {}) //=> 'false' isNumber(Infinity) //=> 'false' isNumber(NaN) //=> 'false' isNumber(new Array('abc')) //=> 'false' isNumber(new Array(2)) //=> 'false' isNumber(new Buffer('abc')) //=> 'false' isNumber(null) //=> 'false' isNumber(undefined) //=> 'false' isNumber({abc: 'abc'}) //=> 'false' ``` ## About ### Related projects * [even](https://www.npmjs.com/package/even): Get the even numbered items from an array. | [homepage](https://github.com/jonschlinkert/even "Get the even numbered items from an array.") * [is-even](https://www.npmjs.com/package/is-even): Return true if the given number is even. | [homepage](https://github.com/jonschlinkert/is-even "Return true if the given number is even.") * [is-odd](https://www.npmjs.com/package/is-odd): Returns true if the given number is odd. | [homepage](https://github.com/jonschlinkert/is-odd "Returns true if the given number is odd.") * [is-primitive](https://www.npmjs.com/package/is-primitive): Returns `true` if the value is a primitive. | [homepage](https://github.com/jonschlinkert/is-primitive "Returns `true` if the value is a primitive. ") * [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.") * [odd](https://www.npmjs.com/package/odd): Get the odd numbered items from an array. | [homepage](https://github.com/jonschlinkert/odd "Get the odd numbered items from an array.") ### Contributing Pull requests and stars are always welcome. For bugs and feature requests, [please create an issue](../../issues/new). ### Building docs _(This document was generated by [verb-generate-readme](https://github.com/verbose/verb-generate-readme) (a [verb](https://github.com/verbose/verb) generator), please don't edit the readme directly. Any changes to the readme must be made in [.verb.md](.verb.md).)_ To generate the readme and API documentation with [verb](https://github.com/verbose/verb): ```sh $ npm install -g verb verb-generate-readme && verb ``` ### Running tests Install dev dependencies: ```sh $ npm install -d && npm test ``` ### Author **Jon Schlinkert** * [github/jonschlinkert](https://github.com/jonschlinkert) * [twitter/jonschlinkert](http://twitter.com/jonschlinkert) ### License Copyright © 2016, [Jon Schlinkert](https://github.com/jonschlinkert). Released under the [MIT license](https://github.com/jonschlinkert/is-number/blob/master/LICENSE). *** _This file was generated by [verb-generate-readme](https://github.com/verbose/verb-generate-readme), v0.1.30, on September 10, 2016._