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.

Install

Install with npm

$ npm i is-number --save

Usage

var isNumber = require('is-number');

true

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'

False

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'

Other projects

• even: Get the even numbered items from an array. | homepage
• is-even: Return true if the given number is even. | homepage
• is-odd: Returns true if the given number is odd. | homepage
• is-primitive: Returns true if the value is a primitive. | homepage
• kind-of: Get the native type of a value. | homepage
• odd: Get the odd numbered items from an array. | homepage

Contributing

Pull requests and stars are always welcome. For bugs and feature requests, please create an issue.

Run tests

Install dev dependencies:

$ npm i -d && npm test

Author

Jon Schlinkert

• github/jonschlinkert
• twitter/jonschlinkert

License

Copyright © 2015 Jon Schlinkert Released under the MIT license.

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This file was generated by verb-cli on November 22, 2015.