PHP's fmod in JavaScript

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

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module.exports = function fmod (x, y) {
// discuss at: http://locutus.io/php/fmod/
// original by: Onno Marsman (https://twitter.com/onnomarsman)
// input by: Brett Zamir (http://brett-zamir.me)
// bugfixed by: Kevin van Zonneveld (http://kvz.io)
// example 1: fmod(5.7, 1.3)
// returns 1: 0.5

var tmp
var tmp2
var p = 0
var pY = 0
var l = 0.0
var l2 = 0.0

tmp = x.toExponential().match(/^.\.?(.*)e(.+)$/)
p = parseInt(tmp[2], 10) - (tmp[1] + '').length
tmp = y.toExponential().match(/^.\.?(.*)e(.+)$/)
pY = parseInt(tmp[2], 10) - (tmp[1] + '').length

if (pY > p) {
p = pY
}

tmp2 = (x % y)

if (p < -100 || p > 20) {
// toFixed will give an out of bound error so we fix it like this:
l = Math.round(Math.log(tmp2) / Math.log(10))
l2 = Math.pow(10, l)

return (tmp2 / l2).toFixed(l - p) * l2
} else {
return parseFloat(tmp2.toFixed(-p))
}
}
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How to use

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

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
1fmod(5.7, 1.3)0.5

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