forked from lix-project/lix-website
77 lines
2.1 KiB
Markdown
77 lines
2.1 KiB
Markdown
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# is-natural-number.js
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[](https://www.npmjs.com/package/is-natural-number)
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[](https://github.com/shinnn/is-natural-number.js/releases)
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[](https://travis-ci.org/shinnn/is-natural-number.js)
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[](https://coveralls.io/r/shinnn/is-natural-number.js?branch=master)
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[](https://david-dm.org/shinnn/is-natural-number.js#info=devDependencies)
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Check if a value is a [natural number](https://wikipedia.org/wiki/Natural_number)
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## Installation
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### Package managers
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#### [npm](https://www.npmjs.com/)
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```
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npm install is-natural-number
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```
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#### [Bower](http://bower.io/)
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```
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bower install is-natural-number
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```
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#### [Duo](http://duojs.org/)
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```javascript
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var isNaturalNumber = require('shinnn/is-natural-number.js');
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```
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### Standalone
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[Download the script file directly.](https://raw.githubusercontent.com/shinnn/is-natural-number.js/master/is-natural-number.js)
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## API
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### isNaturalNumber(*number*, *option*)
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*number*: `Number`
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*option*: `Object`
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Return: `Boolean`
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It returns `true` if the first argument is one of the natural numbers. If not, or the argument is not a number, it returns `false`.
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```javascript
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isNaturalNumber(10); //=> true
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isNaturalNumber(-10); //=> false
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isNaturalNumber(10.5); //=> false
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isNaturalNumber(Infinity); //=> false
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isNaturalNumber('10'); //=> false
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```
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*Check [the test](./test.js) for more detailed specifications.*
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#### option.includeZero
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Type: `Boolean`
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Default: `false`
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By default the number `0` is not regarded as a natural number.
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Setting this option `true` makes `0` regarded as a natural number.
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```javascript
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isNaturalNumber(0); //=> false
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isNaturalNumber(0, {includeZero: true}); //=> true
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```
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## License
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Copyright (c) 2014 - 2016 [Shinnosuke Watanabe](https://github.com/shinnn)
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Licensed under [the MIT License](./LICENSE).
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