`int mt_rand`

([int min], [int max]); Many 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. **mt_rand()** function is a drop-in
replacement for this. It uses a random number generator with
known characteristics, the Mersenne Twister, which will produce
random numbers that should be suitable for cryptographic purposes
and is four times faster than what the average libc provides. The
Homepage of the Mersenne Twister can be found at http://www.math.keio.ac.jp/~matumoto/emt.html,
and an optimized version of the MT source is available from
http://www.scp.syr.edu/~marc/hawk/twister.html.

If called without the optional min,max arguments
**mt_rand()** returns a pseudo-random value
between 0 and RAND_MAX. If you want a random number between 5
and 15 (inclusive), for example, use mt_rand(5,15).

Remember to seed the random number generator before use with
**mt_srand()**.

See also **mt_srand()**,
**mt_getrandmax()**,
**srand()**,
**rand()** and
**getrandmax()**.