(PHP 4, PHP 5, PHP 7, PHP 8)
rand — Generate a random integer
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)
.
Questa funzione non genera valori crittograficamente sicuri, e non dovrebbe essere usata per scopi di crittografia. Se c'è necessità di utilizzare un valore crittograficamente sicuro, si preferisca openssl_random_pseudo_bytes().
Nota: On some platforms (such as Windows), getrandmax() is only 32767. If you require a range larger than 32767, specifying
min
andmax
will allow you to create a range larger than this, or consider using mt_rand() instead.
Nota: 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 thanmin
as opposed to returningfalse
as mt_rand().
min
The lowest value to return (default: 0)
max
The highest value to return (default: getrandmax())
A pseudo random value between min
(or 0) and max
(or getrandmax(), inclusive).
Versione | Descrizione |
---|---|
7.2.0 | 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(). |
Example #1 rand() example
<?php
echo rand(), "\n";
echo rand(), "\n";
echo rand(5, 15), "\n";
?>
Il precedente esempio visualizzerà qualcosa simile a:
7771 22264 11
min
max
range must
be within the range getrandmax(). i.e. (max
-
min
) <= getrandmax()
Otherwise, rand() may return poor-quality random numbers.