(PHP 4, PHP 5, PHP 7)
mt_rand — Generate a random value via the Mersenne Twister Random Number Generator
mt_rand ( ) : int
mt_rand ( int $min , int $max ) : int
This function does not generate cryptographically secure values, and should not be used for cryptographic purposes. If you need a cryptographically secure value, consider using random_int(), random_bytes(), or openssl_random_pseudo_bytes() instead.
Many random number generators of older libcs have dubious or unknown characteristics and are slow. The mt_rand() function is a drop-in replacement for the older rand(). 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).
min
Optional lowest value to be returned (default: 0)
max
Optional highest value to be returned (default: mt_getrandmax())
A random integer value between min (or 0) and max (or mt_getrandmax(), inclusive), or false if max is less than min.
| Version | Description |
|---|---|
| 7.2.0 | mt_rand() has received a bug fix for a modulo bias bug. This means that sequences generated with a specific seed may differ from PHP 7.1 on 64-bit machines. |
| 7.1.0 | rand() has been made an alias of mt_rand(). |
| 7.1.0 | mt_rand() has been updated to use the fixed, correct, version of the Mersenne Twister algorithm. To fall back to the old behaviour, use mt_srand() with MT_RAND_PHP as the second parameter. |
Example #1 mt_rand() example
<?php echo mt_rand() . "\n"; echo mt_rand() . "\n"; echo mt_rand(5, 15); ?>
The above example will output something similar to:
1604716014 1478613278 6
min max range must be within the range mt_getrandmax(). i.e. (max - min) <= mt_getrandmax() Otherwise, mt_rand() may return poorer random numbers than it should.
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https://www.php.net/manual/en/function.mt-rand.php