c# how to declare an interface code example

Example 1: doest all the methos in interface need to implement c#

You have two choices:

- implement every method required by the interface
or
- declare the missing methods abstract in your class. This forces you
to declare your class abstract and, as a result, forces you to
subclass the class (and implement the missing methods) before you
can create any objects.

Example 2: creating interface in C#

using System;

namespace Grepper_Docs
{
    public interface IWhatever
    {
        bool doSomething(); //Interface methods don't have bodies or modifiers
    }
  
  	class Program : IWhatever
    {
        static void Main(string[] args)
        {
            var pro = new Program();
            pro.doSomething();
        }

        public bool doSomething() //methods must be public
        {
            return true;
        }
    }
}