How to Add multiple key to a session variable in laravel

I'm trying to store Shopping cart data into session variable in laravel, till now this is how i was doing in my php project

if (isset($_SESSION["cart_products"])) {  //if session var already exist
        if (isset($_SESSION["cart_products"][$item_id])) { //check item exist in products array
            unset($_SESSION["cart_products"][$item_id]); //unset old array item
        }
    }

After this I was adding that item data into session again to avoid duplicate like shown below

$_SESSION["cart_products"][$item_id] = array("Item_name" => $title,
"Price" => $price, 
"Item_id" => $item_id, 
"User_id" => $user); //update or create product session with new item 

Now how i can achieve the above same method in laravel

This is how i'm trying

if (Session::has('cart_products')) {  //if session var already exist
     if (Session::has("cart_products".$item_id)) { //check item exist in products array
     Session::forget('cart_products'.$item_id); //unset old array item
     }
} 

via Chebli Mohamed