rand
Generate a random integer
Description
int rand()
int rand(int $min, int $max)
If called without the optional min,
max arguments rand
returns a pseudo-random integer between 0 and
getrandmax. If you want a random number
between 5 and 15 (inclusive), for example, use rand(5,
15).
Caution
This function does not generate cryptographically secure values, and must not
be used for cryptographic purposes, or purposes that require returned values to be unguessable.
If cryptographically secure randomness is required, the Random\Randomizer may be
used with the Random\Engine\Secure engine. For simple use cases, the random_int
and random_bytes functions provide a convenient and secure API that is backed by
the operating system’s CSPRNG.
Note:
On some platforms (such as Windows), getrandmax
is only 32767. If you require a range larger than 32767, specifying
min and max will allow
you to create a range larger than this, or consider using
mt_rand instead.
Note: As of PHP 7.1.0, rand uses the same
random number generator as mt_rand. To preserve
backwards compatibility rand allows
max to be smaller than min
as opposed to returning false as mt_rand.
Parameters
-
min
-
The lowest value to return (default: 0)
-
max
-
The highest value to return (default: getrandmax)
Return Values
A pseudo random value between min
(or 0) and max (or getrandmax, inclusive).
Examples
Example #1 rand example
<?php
echo rand(), "\n";
echo rand(), "\n";
echo rand(5, 15), "\n";
?>
The above example will output
something similar to:
Notes
Warning
min max range must
be within the range getrandmax. i.e. (max -
min) <= getrandmax
Otherwise, rand may return poor-quality random numbers.
See Also
- srand
- getrandmax
- mt_rand
- random_int
- random_bytes