When to use a HashTable

Question

In C#, I find myself using a List, IList or IEnumerable 99% of the time. Is there a case when it would be b

Answer 1

Hashtable optimizes lookups. It computes a hash of each key you add. It then uses this hash code to look up the element very quickly. It is an older .NET Framework type. It is slower than the generic Dictionary type.