JavaScript rand
Returns a random number
1 2 3 4 56 7 8 9 1011 12 13 14 1516 17 18 19 2021 22 23 24 2526 27 28 29 3031 32 33 34 3536 37 38 39 4041 42 43 44 4546 47 48 49 5051 52 53 54 55 | function rand (min, max) { // Returns a random number // // version: 1008.1718 // discuss at: http://phpjs.org/functions/rand // + original by: Leslie Hoare // + bugfixed by: Onno Marsman // % note 1: 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; */ } |
Examples
Running
1 | rand(1, 1); |
Should return
1 | 1 |
Dependencies
No dependencies, you can use this function standalone.
Open syntax issues
php.js uses JsLint to help us keep our code consistent and prevent some common bugs.
Eventually we want all code to pass or at least take into consideration most fixes suggested by JsLint, following this JsLint configuration we’ve decided on.
Authors
Thanks to the following developers, you get to have rand goodness in JavaScript.
Kevin van Zonneveld
1 Feb '09 
@ taith: Sorry I don't have a lot of time to really dig in the sources. It would be great if your could explain what makes your implementation better than the one provided by Waldo?
taith
1 Feb '09
[CODE="Javascript"]
function range(start, stop, step) {
if (!arguments.length) return [];
var min, max, step;
if (arguments.length == 1) {
min = 0;
max = arguments[0]-1;
step = 1;
}else{
min = arguments[0];
max = arguments[1];
step = arguments[2] || 1;
}
if (step < 0 && min >= max) {
step *= -1;
var tmp = min;
min = max;
max = tmp;
min += ((max-min) % step);
}
var a = [];
for (var i = min; i <= max; i += step) a[i] = i;
return a;
}
[/CODE]
rtretretetert
Apr 12th