Tryit Editor v2.3

PHP Source:

<!DOCTYPE html>
<html>
<body>

<?php
function myfunction($v)
{
if ($v==="Dog")
  {
  return "Fido";
  }
return $v;
}

$a=array("Horse","Dog","Cat");
print_r(array_map("myfunction",$a));
?>

</body>
</html>