GMP Functions
PHP Manual

gmp_gcd

Calculate GCD

Description

resource gmp_gcd ( resource $a , resource $b )

Calculate greatest common divisor of a and b. The result is always positive even if either of, or both, input operands are negative.

Parameters

a

It can be either a GMP number resource, or a numeric string given that it is possible to convert the latter to a number.

b

It can be either a GMP number resource, or a numeric string given that it is possible to convert the latter to a number.

Return Values

A positive GMP number that divides into both a and b.

Examples

Example #1 gmp_gcd example

<?php
$gcd = gmp_gcd("12", "21");
echo gmp_strval($gcd) . "\n";
?>

The above example will output:

3