session di ci

<?php
	class Sessi extends controller{
 
		function index(){
			echo "ini untuk latihan session";
 
			 $shopping_cart = array(
			'user_id' => 1,
			'number_of_items' => '4',
                        'cart_value' => '34.55'
		);
		$this->session->set_userdata($shopping_cart);
 
		}
 
		function check(){
 
		$user_id      = $this->session->userdata('user_id');
		$items        = $this->session->userdata('number_of_items');
		$total_amount = $this->session->userdata('cart_value');
 
		echo "$items";
 
		}
 
 
	}