Question

I have a custom class containing 2 public variables: 1 is a string and 1 is an integer. I then make a list of this class, in the list I need the string of the class to be unique, if the string already exists in the list I don’t want to add it again but I do want to combine the corresponding integers. here is an example of the custom class and list.

public class myItems
{
    public string itemName;
    public int count;
}

List<myItems> items = new List<myItems>();

myItems e = new myItems();
e.symbol = "pencil";
e.count = 3;
items.Add(e);

myItems e1 = new myItems();
e1.symbol = "eraser";
e1.count = 4;
items.Add(e1);

myItems e2 = new myItems();
e1.symbol = "pencil";
e1.count = 3;
items.Add(e5);

So for the final list i want to it contain: pencil 7, eraser 4. I have been using the contains function on the list to check if it already exists but it only returns true if both the string and integer are the same.

Is there a way to only match on the string?

Answer 1

Another way to do it would be to use LINQ:

public class myItems
{
    public string itemName;
    public int count;
}

List<myItems> items = new List<myItems>();

myItems e = new myItems();
e.symbol = "pencil";
e.count = 3;
Add(items, e);

myItems e1 = new myItems();
e1.symbol = "eraser";
e1.count = 4;
Add(items, e1);

myItems e2 = new myItems();
e1.symbol = "pencil";
e1.count = 3;
Add(items, e5);

public void Add(List<myItems> list, myItems newItem)
{
    var item = list.SingleOrDefault(x => x.symbol == newItem.symbol);

    if(item != null)
    {
        item.count += newItem.count;
    }
    else
    {
        list.Add(newItem);
    }
}