Create object Using Abstract and Interface and its difference

Interface Class

interface InterfaceA

{

    string MethodA(string s);

}

Abstract Class

public class AbstractB:InterfaceA

{

    public string MethodA(string s)

    {

        return s;

    }

}

Object Creation Using Abstract 

AbstractB abstractB = new AbstractB();

abstractB.MethodA("Abstract object");

Output : Abstract object

Object Creation Using Interface 

InterfaceA interfaceA = new AbstractB();

interfaceA.MethodA("Interface object");

Output : Interface object

Note (Object Creation Using Interface) :

 Inheriting the interface directly in the Class and creating the object

 public class DerivedClass :InterfaceA

 {

     public string MethodA(string s)

     {

         return s;

     }

 }

InterfaceA interfaceA1 = new DerivedClass();

interfaceA1.MethodA("Derived object");

Output : Derived object