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

License

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

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