Question

What is implicit and explicit implementation of interfaces? In which scenario it uses? why its need ? in dot net

Answer 1

Implicit implementation is when you implement the interface member without specifying the interface name at the same time.

public interface IFoo 
{
    void Bar();
}

public class ClassA : IFoo 
{
    //this is implicit
    public void Bar() 
    {

    }
}

public class ClassB : IFoo 
{
    //this is explicit:
    void IFoo.Bar()
    {

    }
}

You need explicit implementation when you implement two (or more) interfaces that have a function/property with the same name and signature. In this case the compiler needs to be specifically told which implementation belongs to which interface.