Custom class list seen as "none" in inspector.

As shown below, i’ve made all the implementation as far as i know and it seen as none in the inspector when run the game.

public class item_database : MonoBehaviou![180253-screenshot-3.png|374x261](upload://uO5LJHDONR1DFiTQ14YLj086wFT.png)r
{
    public Sprite[] spriteboxes;


    public List<item> items;

    void Start()
    {
        items = new List<item>();
        set_database();
    }

   

    void set_database()
    {
        items.Add(new item(item.itemType.food, 0, "carrot", "garden food", spriteboxes[0]));
        items.Add(new item(item.itemType.food, 1, "red mushroom", "wild food",spriteboxes[1]));
        items.Add(new item(item.itemType.food, 2, "mushroom", "wild food", spriteboxes[2]));

      
    }

}

I fixed the issue, just remove the monobehabiour inheritance from item class (custom class one)