Summery Summery
Generates a random number.
Syntax Syntax
Parameters Parameters
- $min
-
(Required) Lower limit for the generated number
- $max
-
(Required) Upper limit for the generated number
Return Return
(int) A random number between min and max
Source Source
File: wp-includes/pluggable.php
* @since 2.6.2 * @since 4.4.0 Uses PHP7 random_int() or the random_compat library if available. * * @global string $rnd_value * * @param int $min Lower limit for the generated number * @param int $max Upper limit for the generated number * @return int A random number between min and max */ function wp_rand( $min = 0, $max = 0 ) { global $rnd_value; // Some misconfigured 32-bit environments (Entropy PHP, for example) // truncate integers larger than PHP_INT_MAX to PHP_INT_MAX rather than overflowing them to floats. $max_random_number = 3000000000 === 2147483647 ? (float) '4294967295' : 4294967295; // 4294967295 = 0xffffffff // We only handle ints, floats are truncated to their integer value. $min = (int) $min; $max = (int) $max; // Use PHP's CSPRNG, or a compatible method. static $use_random_int_functionality = true; if ( $use_random_int_functionality ) { try { $_max = ( 0 != $max ) ? $max : $max_random_number; // wp_rand() can accept arguments in either order, PHP cannot. $_max = max( $min, $_max ); $_min = min( $min, $_max ); $val = random_int( $_min, $_max ); if ( false !== $val ) { return absint( $val ); } else { $use_random_int_functionality = false; } } catch ( Error $e ) { $use_random_int_functionality = false; } catch ( Exception $e ) { $use_random_int_functionality = false; } } // Reset $rnd_value after 14 uses. // 32 (md5) + 40 (sha1) + 40 (sha1) / 8 = 14 random numbers from $rnd_value. if ( strlen( $rnd_value ) < 8 ) { if ( defined( 'WP_SETUP_CONFIG' ) ) { static $seed = ''; } else { $seed = get_transient( 'random_seed' ); } $rnd_value = md5( uniqid( microtime() . mt_rand(), true ) . $seed ); $rnd_value .= sha1( $rnd_value ); $rnd_value .= sha1( $rnd_value . $seed ); $seed = md5( $seed . $rnd_value ); if ( ! defined( 'WP_SETUP_CONFIG' ) && ! defined( 'WP_INSTALLING' ) ) { set_transient( 'random_seed', $seed ); } } // Take the first 8 digits for our value. $value = substr( $rnd_value, 0, 8 ); // Strip the first eight, leaving the remainder for the next call to wp_rand(). $rnd_value = substr( $rnd_value, 8 );
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Changelog Changelog
Version | Description |
---|---|
4.4.0 | Uses PHP7 random_int() or the random_compat library if available. |
2.6.2 | Introduced. |