Difference Between Dictionary And Hashtable In C#

Dictionary and Hashtable are both used to hold the data as key-value pairs in C#.

Here, I am providing some basic differences between Dictionary and Hashtable. Whenever we need to decide what to use (Dictionary or Hashtable) for the purpose to hold the data in key-value pairs, please keep in mind about the points given below.

Dictionary

1. Dictionary is generic type Dictionary<TKey,TValue>
2. Dictionary class is a strong type < TKey,TValue > Hence, you must specify the data types for key and value.
3. There is no need of boxing/unboxing.
4. When you try to access non existing key dictionary, it gives runtime error.
5. Dictionary maintains an order of the stored values.
6. There is no need of boxing/unboxing, so it is faster than Hashtable.

Hashtable

1. Hashtable is non-generic type.
2. Hashtable is a weakly typed data structure, so you can add keys and values of any object type.
3. Values need to have boxing/unboxing.
4. When you try to access non existing key Hashtable, it gives null values.
5. Hashtable never maintains an order of the stored values.
6. Hashtable needs boxing/unboxing, so it is slower than Dictionary.