wp_rand
Generates a random number.
Description
Returns (int)
A random number between min and max
Parameters (2)
- 0. $min — Optional. (int)
- Lower limit for the generated number
- 1. $max — Optional. (int)
- Upper limit for the generated number
Usage
if ( !function_exists( 'wp_rand' ) ) { require_once ABSPATH . WPINC . '/pluggable.php'; } // Lower limit for the generated number $min = -1; // Upper limit for the generated number $max = -1; // NOTICE! Understand what this does before running. $result = wp_rand($min, $max);
Defined (1)
The function is defined in the following location(s).
- /wp-includes/pluggable.php
- function wp_rand( $min = 0, $max = 0 ) {
- global $rnd_value;
- // Some misconfigured 32bit 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);
- $value = abs(hexdec($value));
- // Reduce the value to be within the min - max range
- if ( $max != 0 )
- $value = $min + ( $max - $min + 1 ) * $value / ( $max_random_number + 1 );
- return abs(intval($value));
- }