mt_rand

 int mt_rand ( void ) 

説明

random number generators of older libcs have dubious or unknown characteristics and are slow. By default, PHP uses the libc random number generator with the rand() function. The mt_rand() function is a drop-in replacement for this. It uses a random number generator with known characteristics using the »  Mersenne Twister, which will produce random numbers four times faster than what the average libc rand() provides. If called without the optional min, max arguments mt_rand() returns a pseudo-random value between 0 and mt_getrandmax(). If you want a random number between 5 and 15 (inclusive), for example, use mt_rand(5, 15).

戻り値

A random integer value between min (or 0) and max (or mt_getrandmax(), inclusive)