Invoker (TextEditor): ○ The TextEditor class is the invoker that invokes commands. It holds a stack of commands (_commandHistory) and is responsible for executing

Short answer: And undoing commands. When a command is executed, it’s pushed onto the stack. The Undo() method pops the last executed command and undoes its ction. public class TextEditor { private readonly Stack<ICommand> _commandHistory = new Stack<ICommand>(); public void ExecuteCommand(ICommand command) { command.Execute(); _commandHistory.Push(command); } public… void… nd undoing commands. When a command is executed, it’s…

Explain a bit more

pushed onto the stack. The Undo() method pops the last executed command and undoes its ction. public class TextEditor { private readonly Stack<ICommand> _commandHistory = new Stack<ICommand>(); public void ExecuteCommand(ICommand command) { command.Execute(); _commandHistory.Push(command); } public void Undo() { if (_commandHistory.Count > 0) { var command = _commandHistory.Pop(); command.Undo(); } } } And undoing commands. When a command is executed, it’s pushed onto the stack. The Undo() method pops the last executed command and undoes its ction. public class TextEditor { private readonly Stack<ICommand> _commandHistory = new… { command.Execute(); _commandHistory.Push(command); }

Example code

public void Undo()
{
if (_commandHistory.Count > 0)
{
var command = _commandHistory.Pop(); command.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.