namespace InterFaceDemo
{
//defining First interface
interface ISum
{
void sum(int a, int b);
}
//defining second interface which inherits first interface
interface ISubtract:ISum
{
void sub(int a, int b);
}
//defining class which inherits second interface
class NewClass : ISubtract
{
//implementing interface defined methods
public void sum(int a, int b)
{
Console.WriteLine((a+b).ToString());
}
public void sub(int a, int b)
{
Console.WriteLine((a-b).ToString());
}
}
class Program
{
static void Main(string[] args)
{
//creating instance of class
NewClass newclass = new NewClass();
//calling sum() of ISum interface
newclass.sum(4,5);
//calling sub() of ISubtract interface
newclass.sub(5,8);
}
}
}
here i want to know that we have use interface .But we can call add and subtract method with out use interface.then what is need of interface .