数组和$ _REQUEST

I need to use Ajax DataTable.
Order request is in array.
On inspect: Request parametersid: order[0][column]:"4" , order[0][dir]:"asc" and start:"0" .

If i want to get value of "start" i use:

$str=$_REQUEST['start'];

Now i don't know how to get value "4" and "asc"?

I have tried with this (current(current($_REQUEST['order']))) and it returns "4", but for "asc", until now. no solution found.

Check values of

$_REQUEST['order'][0]["column"] 

and

$_REQUEST['order'][0]["dir"]

Try:

$str = $_REQUEST['order'][0]['column'];

and

$str2 = $_REQUEST['order'][0]['dir'];