One interface can inherit another. : Interface hierarchy « Class « C# / CSharp Tutorial

1. C# / CSharp Tutorial
2. Class
3. Interface hierarchy

using System; 
 
public interface BaseInterface { 
  void meth1(); 
  void meth2(); 
} 
 
// BaseInterface now includes meth1() and meth2() -- it adds meth3(). 
public interface BaseInterface2 : BaseInterface { 
  void meth3(); 
} 
 
// This class must implement all of BaseInterface and BaseInterface 
class MyClass : BaseInterface2 { 
  public void meth1() { 
    Console.WriteLine("Implement meth1()."); 
  } 
 
  public void meth2() { 
    Console.WriteLine("Implement meth2()."); 
  } 
 
  public void meth3() { 
    Console.WriteLine("Implement meth3()."); 
  } 
} 
 
class MainClass { 
  public static void Main() { 
    MyClass ob = new MyClass(); 
 
    ob.meth1(); 
    ob.meth2(); 
    ob.meth3(); 
  } 
}

Implement meth1().
Implement meth2().
Implement meth3().