function foo()
{
   $numargs = func_num_args(); // number of arguments
   
   if ($numargs >= 2) {
       echo "Second argument is: " . func_get_arg(1) . "<br />\n";
   }
   $arg_list = func_get_args(); // all arguments as an array
   for ($i = 0; $i < $numargs; $i++) {
       echo "Argument $i is: " . $arg_list[$i] . "<br />\n";
   }
}

foo(1, 2, 3);
foo(1, 2, 3, 4, 5);

allows for variable length arguments - something similar as python
func(*args, **kw)

php variable length arguments

php

PHP