js_mt_rand

A pseudo-random generator that can produce the same numbers as php's mt_rand do with given seed.

the javascript version of 32-bit php_mt_rand; ported from php-src/ext/standard/mt_rand.c

Install

via npm

$ npm install js_mt_rand

via yarn

$ yarn add js_mt_rand

Usage

import JSMTRand from 'js_mt_rand';

let mt = new JSMTRand();

// seed the generator
mt.srand(0);

// php 7.1+ Mersenne Twister implementation (default)
mt.srand(0, JSMTRand.MODE_MT_RAND_19937);

// get next random number, range: [0, 2 ^ 32 - 1)
// N.B. MODE_MT_RAND_19937 has a wider range than MODE_MT_RAND_PHP
let m = mt.rand(0, 0xFFFFFFFF);

// php 5.x backward compatibility.
mt.srand(0, JSMTRand.MODE_MT_RAND_PHP);

// get next random number, range: [0, 2 ^ 31 - 1]
let n = mt.rand();

// get next random number in range: [min, max], max is inclusive
let r = mt.rand(min, max);

Pitfall

Due to the PHP 7.1.0 to 7.2.0beta2 mt_rand() modulo bias bug, the JSMTRand.rand(min, max) may return different results between php 7.1.0 to 7.2.0beta2, just use JSMTRand.rand() instead and wrap your own range function.

Since the bip operators in javascript are not support 64 bits integer yet, the generator would only work with 32 bits range.

Changelog

See CHANGELOG

License

The MIT License (MIT)

Credits

Authors of PHP 7.1+: Rasmus Lerdorf, Zeev Suraski, Pedro Melo, Sterling Hughes.

Based on code from: Richard J. Wagner, Makoto Matsumoto, Takuji Nishimura, Shawn Cokus.