Hashset, HashTable in c#

HashSet - 
  • This is an optimized set collection. It helps eliminates duplicate strings or elements in an array.
  • This internally calls the UnionWith method to eliminate the duplications. 
  • It has OverLap, SymmetricExceptWith
    • OverLap - This method returns true or false. It tests to see if any of the HashSet's elements are contained in the IEnumerable argument's elements. Only one equal element is required.

    • SymmetricExceptWith - This method returns only those don't match in the collection.

HashTable -

  • The Hashtable class represents a collection of key-and-value pairs that are organized based on the hash code of the key. It uses the key to access the elements in the collection. 
  • A hash table is used when you need to access elements by using key, and you can identify a useful key value.
  • This 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. But if an old program uses Hashtable, it is helpful to know how to use this type.





































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