Command Interface (ICommand):?

Short answer: The ICommand interface defines two methods: ■ Execute(): Executes the command. ■ Undo(): Reverts the command if the user wishes to undo the action. public interface ICommand

Example code

{ void Execute(); void Undo(); }

Real-world example (ShopNest)

Use a GoF pattern in ShopNest only when it removes duplication or makes a change safer—explain the problem it solves in the interview.

Say this in the interview

1. Define — one clear sentence (the short answer above).
2. Example — relate it to a project like ShopNest or your real work.
3. Trade-off — when you would not use it.