If you’ve ever used PHP’s library functions you’ve most likely noticed that several function such as array() can take an indeterminate number of arguments. Normally when defining a function you specify each argument in the function declaration. Obviously it would be impossible to define an infinite number of arguments in such a way. PHP does, however, allow you to accomplish this through the function func_get_args().

func_get_args() returns an array consisting of all of the arguments passed to a function. Using this method you can bypass the conventional method of defining parameters in the function definition all-together. Here is an example:

function add()
{
	$total = 0;
	$args = func_get_args();
	foreach($args as $arg)
	{
		if(is_numeric($arg))
			$total += $arg;
	}
	return $total;
}
echo add(1, 2, 3); //will return 6

If for whatever reason you need to know the total number of arguments passed to a function, PHP provides the func_num_args() function.

When retrieving arguments in this manner it is important to remember that func_get_args only returns an array of arguments passed by the user. It does not account for default values.