multidimensional array help pls

hi will try to make a per world inventory and my plan it i safe in a multiplearray but i don know how to call a array in array i have that never learn here my array from my brain:

PHP:

private $lvl = array("world"=>array("playername"=>array("slot"=>array("0"=>array("id"=>1,"count"=10),"1"=>array("id"=>12"count"=>20)))));

i dont know how ro call a aaray in array or a array in a array thaht is in a array and more

 

https://www.w3schools.com/php/php_arrays_multidimensional.asp

 

thanks i have learn php with sololearn and the show that ecist multidimensional array but not how to call a array in a array