GMP Functions
PHP Manual

gmp_random_seed

Sets the RNG seed

Description

mixed gmp_random_seed ( mixed $seed )

Parameters

seed

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

Either a GMP number resource in PHP 5.5 and earlier, a GMP object in PHP 5.6 and later, or a numeric string provided that it is possible to convert the latter to a number.

Return Values

Returns NULL on success.

Errors/Exceptions

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

Examples

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'));

The above example will output:

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)

See Also

  • gmp_init
  • gmp_random
  • gmp_random_bits
  • gmp_random_range