Derived but editable: linkedSignal in Angular
Angular interview exercise on Signals, difficulty 3 of 3. Solve it in the editor beside a worked example, or cold in Interview mode with the example hidden; the tests run the moment you do.
Finish ShippingPickerComponent: `methods` is computed from the country (DE: DHL and Hermes; anything else: UPS and FedEx), and `selected` defaults to the first method, can be changed by clicking one, and goes back to the first method whenever the country changes.
Each exercise pairs a worked example with a twin problem to solve in a real editor; the tests run the moment you do. Interview mode hides the example: solve it from memory, without the hint or the solution, and it counts as solved cold. Progress is saved in your browser, and in your account if you sign in.