PHP 7.1.21 Released

gmp_random_seed

(PHP 7)

gmp_random_seedSets the RNG seed

说明

void gmp_random_seed ( mixed $seed )

参数

seed

The seed to be set for the gmp_random(), gmp_random_bits(), and gmp_random_range() functions.

可以是一个 GMP 数据 resouce,或一个可以转换为数值的字符串。

返回值

Returns NULL on success 或者在失败时返回 FALSE.

错误/异常

Issues an E_WARNING and returns FALSE if seed is not valid.

范例

Example #1 gmp_random_seed() example

<?php
// set the seed
gmp_random_seed(100);

var_dump(gmp_strval(gmp_random(1)));

// set the seed to something else
gmp_random_seed(gmp_init(-100));

var_dump(gmp_strval(gmp_random_bits(10)));

// set the seed to something invalid
var_dump(gmp_random_seed('not a number'));

以上例程会输出:

string(20) "15370156633245019617"
string(3) "683"

Warning: gmp_random_seed(): Unable to convert variable to GMP - string is not an integer in %s on line %d
bool(false)

参见

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