Question

i have a small sample .

//Class
public class GetEntity
 {
   public string name1 { get; set; }
   public string name2 { get; set; }
   public GetEntity() { }
 }

and:

public void GetHash()
   {
     HashSet objHash = new HashSet();
     GetEntity obj = new GetEntity();
     obj.name1 = "Ram";
     obj.name2 = "Shyam";
     objHash.Add(obj);
     foreach (GetEntity objEntity in objHash)
      {
        Label2.Text = objEntity.name1.ToString() + objEntity.name2.ToString();
      }

   }

Code works fine.Same task is done through Dictionary and List.But i want to know when we use HashSet<> , Dictionary<> or List<>.Is there only performance issue or any other things which i dont understand.Thanks.

Answer 1

i want to know when we use HashSet<> , Dictionary<> or <List>

They all have different purpose and used in different scenarios

HashSet

Is used when you want to have a collection with unique elements. HashSet stores list of unique elements and won’t allow duplicates in it.

Dictionary

Is used when you want to have a value against a unique key. Each element in Dictionary has two parts a (unique) key and a value. You can store a unique key in it (just like Hashset) in addition you can store a value against that unique key.

List

Is just a simple collection of elements. You can have duplicates in it.