rand
rand
(PHP 4, PHP 5, PHP 7)
rand — Generate a random integer
Description
int rand ( void )
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 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.
Note: On some platforms (such as Windows), getrandmax() is only 32767. If you require a range larger than 32767, specifyingminandmaxwill 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 compatibilityrand()allowsmaxto be smaller thanminas opposed to returningFALSEas 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).
Changelog
| Version | Description |
|---|---|
| 7.1.0 | rand() has been made an alias of mt_rand(). |
Examples
Example #1 rand() example
<?php
echo rand() . "\n";
echo rand() . "\n";
echo rand(5, 15
?>
The above example will output something similar to:
7771
22264
11
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() - Seed the random number generator
- getrandmax() - Show largest possible random value
- mt_rand() - Generate a random value via the Mersenne Twister Random Number Generator
- random_int() - Generates cryptographically secure pseudo-random integers
- random_bytes() - Generates cryptographically secure pseudo-random bytes
- openssl_random_pseudo_bytes() - Generate a pseudo-random string of bytes
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