srand
(PHP 4, PHP 5)
srand — Seed the random number generator
Description
void srand
([ int $seed
] )
Seeds the random number generator with seed or with a random value if no seed is given.
Note: As of PHP 4.2.0, there is no need to seed the random number generator with srand() or mt_srand() as this is now done automatically.
Parameters
- seed
-
Optional seed value
Return Values
No value is returned.
Changelog
| Version | Description |
|---|---|
| Since 4.2.0 | The seed becomes optional and defaults to a random value if omitted. |
Examples
Example #1 srand() example
<?php
// seed with microseconds
function make_seed()
{
list($usec, $sec) = explode(' ', microtime());
return (float) $sec + ((float) $usec * 100000);
}
srand(make_seed());
$randval = rand();
?>
See Also
- rand() - Generate a random integer
- getrandmax() - Show largest possible random value
- mt_srand() - Seed the better random number generator