PHP | gmp_random() Function

The gmp_random() function is an inbuilt function in PHP which generates a random number. The range of random number will be in between zero and the number of bits per limb ( A limb is an internal GMP mechanism. The number of bits in a limb is not static and it can vary from system to system. Usually, the number of bits in a limb is either 16 or 32 but this is not always true. ) multiplied by limiter .The number generated depends on the limiter i.e. if the limiter is negative then the number generated will also be negative.

Syntax:

 GMP gmp_random ( int $limiter )

Parameters: The gmp_random() function accepts a single parameter as shown above and explained below:

• $limiter : It is the only required parameter accepted by the gmp_random() function. This parameter sets the limiter value. This parameter can be a GMP resource in PHP 5.5 or earlier, a GMP object in PHP version 5.6 and later, or also allowed to pass a numeric string provided that it is possible to convert that string to a number.

Return Value: This function returns a random number between zero and the number of bits per limb as explained above.

Below programs illustrate the gmp_random() function in PHP.

Program 1:

<?php
// php code implementing gmp_random() function

// random number from 0 to 1 * bits per limb
$rand = gmp_random(1);
echo gmp_strval($rand) . "\n";

?>

Output:

1915834968

Program 2:

<?php
// php code implementing gmp_random() function

// random number from 0 to 2 * bits per limb
$rand = gmp_random(2);
echo gmp_strval($rand) . "\n";

?>

Output:

 8642564075890328087

Reference: http://php.net/manual/en/function.gmp-random.php