phpjs/functions/math/rand.js

php.js offers community built php functions in javascript

function rand(min, max) {
  //  discuss at: http://phpjs.org/functions/rand/
  // original by: Leslie Hoare
  // bugfixed by: Onno Marsman
  //        note: See the commented out code below for a version which will work with our experimental (though probably unnecessary) srand() function)
  //   example 1: rand(1, 1);
  //   returns 1: 1

  var argc = arguments.length;
  if (argc === 0) {
    min = 0;
    max = 2147483647;
  } else if (argc === 1) {
    throw new Error('Warning: rand() expects exactly 2 parameters, 1 given');
  }
  return Math.floor(Math.random() * (max - min + 1)) + min;

  /*
  // See note above for an explanation of the following alternative code

  // +   reimplemented by: Brett Zamir (http://brett-zamir.me)
  // -    depends on: srand
  // %          note 1: This is a very possibly imperfect adaptation from the PHP source code
  var rand_seed, ctx, PHP_RAND_MAX=2147483647; // 0x7fffffff

  if (!this.php_js || this.php_js.rand_seed === undefined) {
    this.srand();
  }
  rand_seed = this.php_js.rand_seed;

  var argc = arguments.length;
  if (argc === 1) {
    throw new Error('Warning: rand() expects exactly 2 parameters, 1 given');
  }

  var do_rand = function (ctx) {
    return ((ctx * 1103515245 + 12345) % (PHP_RAND_MAX + 1));
  };

  var php_rand = function (ctxArg) { // php_rand_r
    this.php_js.rand_seed = do_rand(ctxArg);
    return parseInt(this.php_js.rand_seed, 10);
  };

  var number = php_rand(rand_seed);

  if (argc === 2) {
    number = min + parseInt(parseFloat(parseFloat(max) - min + 1.0) * (number/(PHP_RAND_MAX + 1.0)), 10);
  }
  return number;
  */
}