Why won't a Hashtable return true for “ContainsKey” for a key of type byte[] in C#?

Question

Consider the following code:

byte[] bytes = new byte[] { 1, 2, 5, 0, 6 };
byte[] another = new byte[] { 1, 2, 5, 0, 6 };

Hashtable ht = new Hashtable();
ht.Add(         


        

Answer 1

It returns false because the hashes don't match. If GetHashCode() doesn't produce a repeatable hash for the same value it won't work in a dictionary.

byte[] bytes = new byte[] { 1, 2, 5, 0, 6 };
byte[] another = new byte[] { 1, 2, 5, 0, 6 };

string astring = "A string...";
string bstring = "A string...";

MessageBox.Show(bytes.GetHashCode() + " " + another.GetHashCode() + " | " + astring.GetHashCode() + " " + bstring.GetHashCode());