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gmp_random_seed

PHP function Edit on GitHub ✎

(PHP 7, PHP 8)

Sets the RNG seed

Description

gmp_random_seed(GMP|int|string $seed): void

Parameters

seed

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

Parameter

Return Values

Void

Errors/Exceptions

Throws a ValueError if seed is invalid.

Changelog

Version	Description
8.0.0	If `seed` is invalid, `gmp_random_seed()` now throws a `ValueError`. Previously it emitted an `E_WARNING` and returned false.

Examples

gmp_random_seed() example

php

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

var_dump(gmp_strval(gmp_random_bits(10)));

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

var_dump(gmp_strval(gmp_random_range(0, 100)));

// set the seed to something invalid
try {
    gmp_random_seed('not a number');
} catch (\ValueError $e) {
    echo $e->getMessage(), PHP_EOL;
}

The above example will output:

output

string(3) "800"
string(2) "32"
gmp_random_seed(): Argument #1 ($seed) is not an integer string