Nested Dictionary collection in .NET

Question

The .NET Dictionary object allows assignment of key/values like so:

Dictionary dict = new Dictionary&l         


        

Answer 1

You have to decide on either supporting a fixed number of string keys to look up, or provide a more general key mechanism if the number of keys can vary. For the first case try the following:

Dictionary> dict =
    Dictionary>();
dict["F1"]["F2"] = "foo";
Dictionary>> dict2 =
    Dictionary>();
dict2["F1"]["F2"]["F3"] = "bar";

For the second case, you could do the following:

Dictionary dict = new Dictionary(new MyEqualityComparer());
dict[new string[] {"F1","F2"}] = "foo";
dict[new string[] {"F1","F2","F3"}] = "bar";

where the class MyEqualityComparer would be something like:

public class MyEqualityComparer : IEqualityComparer
{
    public int GetHashCode(string[]item)
    {
         int hashcode = 0;
         foreach (string s in item)
         { 
             hashcode |= s.GetHashCode();
         }
         return hashcode;
    }

    public bool Equals(string [] a, string [] b)
    {
         if (a.Length != b.Length)
             return false;
         for (int i = 0; i < a.Length; ++i)
         {
             if (a[i] != b[i])
                 return false;
         }
         return true;
   }