PHP's is_int in JavaScript

Here’s what our current JavaScript equivalent to PHP's is_int looks like.

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module.exports = function is_int (mixedVar) { // eslint-disable-line camelcase
// discuss at: http://locutus.io/php/is_int/
// original by: Alex
// improved by: Kevin van Zonneveld (http://kvz.io)
// improved by: WebDevHobo (http://webdevhobo.blogspot.com/)
// improved by: Rafał Kukawski (http://blog.kukawski.pl)
// revised by: Matt Bradley
// bugfixed by: Kevin van Zonneveld (http://kvz.io)
// note 1: 1.0 is simplified to 1 before it can be accessed by the function, this makes
// note 1: it different from the PHP implementation. We can't fix this unfortunately.
// example 1: is_int(23)
// returns 1: true
// example 2: is_int('23')
// returns 2: false
// example 3: is_int(23.5)
// returns 3: false
// example 4: is_int(true)
// returns 4: false

return mixedVar === +mixedVar && isFinite(mixedVar) && !(mixedVar % 1)
}
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How to use

You you can install via npm install locutus and require it via require('locutus/php/var/is_int'). You could also require the var module in full so that you could access var.is_int instead.

If you intend to target the browser, you can then use a module bundler such as Browserify, webpack or rollup.js.

ES5/ES6

This function targets ES5, but as of Locutus 2.0.2 we also support ES6 functions. Locutus transpiles to ES5 before publishing to npm.

A community effort

Not unlike Wikipedia, Locutus is an ongoing community effort. Our philosophy follows The McDonald’s Theory. This means that we don't consider it to be a bad thing that many of our functions are first iterations, which may still have their fair share of issues. We hope that these flaws will inspire others to come up with better ideas.

This way of working also means that we don't offer any production guarantees, and recommend to use Locutus inspiration and learning purposes only.

Notes

  • 1.0 is simplified to 1 before it can be accessed by the function, this makes it different from the PHP implementation. We can’t fix this unfortunately.

Examples

Please note that these examples are distilled from test cases that automatically verify our functions still work correctly. This could explain some quirky ones.

#codeexpected result
1is_int(23)true
2is_int('23')false
3is_int(23.5)false
4is_int(true)false

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