Item dictionary with inherited classes

Question

I have something like this:

public class Item
{
    public int itemID;
    public string itemName;
}

public class Tool : Item
{
    public int toolDurability;
}

I want to create a Dictionary, something like

public Dictionary<int,Item> itemDic = new Dictionary<int,Item>();

Where the key is the itemID, and the Item is the Item. This way I have a sort of database to give it some itemID, and it spit back out the appropriate item. The issue is, if I add the class Tool to this dictionary, if I try accessing the dictionary value, it will not give access to the Tool variables (since the dictionary only specifies the top-level "item" class).

If I create several different inherited classes, how would I setup a dictionary to allow me to get the correct class / Type of item, out of the dictionary based on its itemID?

What's the point of having abstraction (Item) if you still have to access specific properties? This looks like bad design. — FCin, Jan 05 '19 at 09:49
Possible duplicate of [Storing derived classes in a base class Dictionary](https://stackoverflow.com/questions/38137073/storing-derived-classes-in-a-base-class-dictionary) — GSerg, Jan 05 '19 at 09:54

score 2 · Accepted Answer · answered Jan 05 '19 at 09:56

You could do the following,.

For input,

Dictionary<int,Item> itemDict = new Dictionary<int,Item>
{
  [1] = new Item(){itemID = 2},
  [2] = new Tool(){itemID=3, toolDurability=4}
};

You can

foreach(KeyValuePair<int, Item> entry in itemDict)
{

  switch(entry.Value)
  {
    case Tool tool:
      Console.WriteLine(tool.toolDurability);
      break;
    case Item item:
      Console.WriteLine(item.itemID);
      break;
   }
 }

Item dictionary with inherited classes

1 Answers1