If your function takes an array parameter. You can check it and access it like this:

Here the call to zend_parse_parameters() does the type check. If the user passes a non-array to this function s/he will get a message that looks like this:

foo.php(4) : Warning - my_arr() expects argument 1 to be array, integer given

If you wanted to write a function that could take either an array of integers or perhaps a single integer and have your function figure it out automatically you do do it like this:

The possible types are: