(PHP 4, PHP 5, PHP 7)
bcmod — Get modulus of an arbitrary precision number
$left_operand
   , string $modulus
   )
   Get the modulus of the left_operand using
   modulus.
  
left_operandThe left operand, as a string.
modulusThe modulus, as a string.
   Returns the modulus as a string, or NULL if 
   modulus is 0.
  
Example #1 bcmod() example
<?php
echo bcmod('4', '2'); // 0
echo bcmod('2', '4'); // 2
?>