Question

I have a few classes in my current project where validation of Email/Website addresses is necessary. The methods to do that are all the same.

I wondered what’s the best way to implement this, so I don’t need to have these methods copy pasted everywhere?

The classes themselves are not necessarily related, they only have those validation methods in common.

Answer 1

How about adding an interface, and using an extension method?

public interface IFoo { }

public class A : IFoo {}
public class B : IFoo {}
public class C : IFoo {}

public static class FooUtils {
    public static void Bar(this IFoo foo) { /* impl */ }
}

That way:

• no unnecessary inheritance
• no duplication