International PHP Conference Berlin 2023

mt_rand

(PHP 4, PHP 5, PHP 7, PHP 8)

mt_randGenerate a random value via the Mersenne Twister Random Number Generator

Açıklama

mt_rand(): int
mt_rand(int $min, int $max): int

Many random number generators of older libcs have dubious or unknown characteristics and are slow. The mt_rand() function is a drop-in replacement for the older rand(). It uses a random number generator with known characteristics using the » Mersenne Twister, which will produce random numbers four times faster than what the average libc rand() provides.

If called without the optional min, max arguments mt_rand() returns a pseudo-random value between 0 and mt_getrandmax(). If you want a random number between 5 and 15 (inclusive), for example, use mt_rand(5, 15).

Dikkat

Bu işlev kriptografik olarak güvenilir değerler üretmez ve kriptografik amaçlarla kullanılmamalıdır. Kriptografik olarak güvenilir bir değere ihtiyaç duyuluyorsa bunun yerine random_int() veya random_bytes() işlevi denenebilir.

Bağımsız Değişkenler

min

Optional lowest value to be returned (default: 0)

max

Optional highest value to be returned (default: mt_getrandmax())

Dönen Değerler

A random integer value between min (or 0) and max (or mt_getrandmax(), inclusive), or false if max is less than min.

Sürüm Bilgisi

Sürüm: Açıklama
7.2.0 mt_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().
7.1.0 mt_rand() has been updated to use the fixed, correct, version of the Mersenne Twister algorithm. To fall back to the old behaviour, use mt_srand() with MT_RAND_PHP as the second parameter.

Örnekler

Örnek 1 mt_rand() example

<?php
echo mt_rand() . "\n";
echo 
mt_rand() . "\n";

echo 
mt_rand(515);
?>

Yukarıdaki örnek şuna benzer bir çıktı üretir:

1604716014
1478613278
6

Notlar

Uyarı

min max range must be within the range mt_getrandmax(). i.e. (max - min) <= mt_getrandmax() Otherwise, mt_rand() may return poorer random numbers than it should.

Ayrıca Bakınız

  • mt_srand() - Seeds the Mersenne Twister Random Number Generator
  • mt_getrandmax() - Show largest possible random value
  • random_int() - Get a cryptographically secure, uniformly selected integer
  • random_bytes() - Get cryptographically secure random bytes
  • rand() - Generate a random integer

add a note

User Contributed Notes 2 notes

up
6
Pawe Krawczyk
9 years ago
To reiterate the message about *not* using mt_rand() for anything security related, here's a new tool that has been just posted that recovers the seed value given a single mt_rand() output:

http://www.openwall.com/php_mt_seed/README
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