PHP 手冊
前一頁 |  | 下一頁

# mt_rand

(PHP 3>= 3.0.6, PHP 4 , PHP 5)

mt_rand -- Generate a better random value

## Description

int mt_rand ( [int min, int max] )

Many random number generators of older libcs have dubious or unknown characteristics and are slow. By default, PHP uses the libc random number generator with the rand() function. The mt_rand() function is a drop-in replacement for this. 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 `RAND_MAX`. If you want a random number between 5 and 15 (inclusive), for example, use mt_rand (5, 15).

範例 1. mt_rand() example

`<?php echo mt_rand() . "\n"; echo mt_rand() . "\n"; echo mt_rand(5, 15); ?>`

The above example will output something similar to:

    1604716014
    1478613278
    6

> 注: 由PHP 4.2.0 始，您不需要再使用 srand() 或 mt_srand() 為亂數產生器提供種子，因為這已自動的提供了。

> 注: In versions before 3.0.7 the meaning of max was range. To get the same results in these versions the short example should be mt_rand (5, 11) to get a random number between 5 and 15.

See also: mt_srand(), mt_getrandmax(), and rand().

前一頁 | 內容 | 下一頁
mt_getrandmax | 上一層 | mt_srand