How To pass Optional Arguments

Question

I have one function having two fixed arguments. But next arguments are not fixed, there can be two or three or four of them.

It's a runtime arguments so how can I define that function?

My code looks like:

public ObservableCollection<ERCErrors> ErrorCollectionWithValue
    (string ErrorDode, int MulCopyNo, dynamic arguments comming it should be 2 or 3)
        {

        return null;
    }

Answer 1

1) params (C# Reference)

public ObservableCollection<ERCErrors>ErrorCollectionWithValue
                (string ErrorDode, int MulCopyNo, params object[] args)
{
    //...
}

2) Named and Optional Arguments (C# Programming Guide)

public ObservableCollection<ERCErrors> ErrorCollectionWithValue
    (string ErrorDode, int MulCopyNo, object arg1 = null, int arg2 = int.MinValue)
{
    //...
}

3) And maybe simple method overloading would still suit better, separating method logic to different methods? Under this link you can also find another description of named and optional parameters