Returns true if the value is a number. comprehensive tests.
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.
Install with npm
$ npm i is-number --save
var isNumber = require('is-number');
See the tests for more examples.
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'
See the tests for more examples.
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'
true
if the value is a primitive. | homepagePull requests and stars are always welcome. For bugs and feature requests, please create an issue.
Install dev dependencies:
$ npm i -d && npm test
Jon Schlinkert
Copyright © 2015 Jon Schlinkert Released under the MIT license.
This file was generated by verb-cli on November 22, 2015.
# is-number [![NPM version](https://badge.fury.io/js/is-number.svg)](http://badge.fury.io/js/is-number) [![Build Status](https://travis-ci.org/jonschlinkert/is-number.svg)](https://travis-ci.org/jonschlinkert/is-number) > Returns true if the value is a number. comprehensive tests. 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). ## Install Install with [npm](https://www.npmjs.com/) ```sh $ npm i is-number --save ``` ## Usage ```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' ``` ## Other projects * [even](https://www.npmjs.com/package/even): Get the even numbered items from an array. | [homepage](https://github.com/jonschlinkert/even) * [is-even](https://www.npmjs.com/package/is-even): Return true if the given number is even. | [homepage](https://github.com/jonschlinkert/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) * [is-primitive](https://www.npmjs.com/package/is-primitive): Returns `true` if the value is a primitive. | [homepage](https://github.com/jonschlinkert/is-primitive) * [kind-of](https://www.npmjs.com/package/kind-of): Get the native type of a value. | [homepage](https://github.com/jonschlinkert/kind-of) * [odd](https://www.npmjs.com/package/odd): Get the odd numbered items from an array. | [homepage](https://github.com/jonschlinkert/odd) ## Contributing Pull requests and stars are always welcome. For bugs and feature requests, [please create an issue](https://github.com/jonschlinkert/is-number/issues/new). ## Run tests Install dev dependencies: ```sh $ npm i -d && npm test ``` ## Author **Jon Schlinkert** + [github/jonschlinkert](https://github.com/jonschlinkert) + [twitter/jonschlinkert](http://twitter.com/jonschlinkert) ## License Copyright © 2015 Jon Schlinkert Released under the MIT license. *** _This file was generated by [verb-cli](https://github.com/assemble/verb-cli) on November 22, 2015._