Description
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. 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 that should
be suitable for seeding some kinds of cryptography (see the home page
for details) and is four times faster than what the average libc
provides.
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).
In older versions of PHP, you had to seed the random number generator
before use with mt_srand(). Since 4.2.0 this is no
longer necessary.
Note:
In versions before 3.0.7 the meaning of
max was range. To
get the same results in these versions the short example should
be mt_rand (5, 11) to get a random number
between 5 and 15.
See also mt_srand(),
mt_getrandmax() and
rand().
