is-number   

Returns true if the value is a number. comprehensive tests.

Install

Install with npm:

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.

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: Get the even numbered items from an array. | [homepage](https://github.com/jonschlinkert/even "Get the even numbered items from an array.")
• 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: 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: 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: Get the native type of a value. | [homepage](https://github.com/jonschlinkert/kind-of "Get the native type of a value.")
• 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 (a 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:

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
• twitter/jonschlinkert

License

Copyright © 2016, Jon Schlinkert. Released under the MIT license.

_This file was generated by verb-generate-readme, v0.1.30, on September 10, 2016._