Difference Between Dictionary And Hashtable In C#

 

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.

"e.g Dictionary<string, string> EmployeeList = new Dictionary<string, string>();  

EmployeeList.Add(""Mahesh Chand"", ""Programmer"");  

EmployeeList.Add(""Praveen Kumar"", ""Project Manager"");  

EmployeeList.Add(""Raj Kumar"", ""Architect"");  

EmployeeList.Add(""Nipun Tomar"", ""Asst. Project Manager"");  

EmployeeList.Add(""Dinesh Beniwal"", ""Manager"");  "

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.

"e.g Hashtable HT = new Hashtable();    

HT.Add(1,""s"");    

HT.Add(3, ""n"");    

HT.Add(4, ""j"");    

HT.Add(2, ""a"");    

HT.Add(5, ""u"");  "