A growing list with FormArray in Angular
Angular interview exercise on Forms, 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.
PhonesComponent keeps phone numbers in a FormArray named `phones` inside `form`, starting empty. <button class="add"> appends an empty control; each entry is an <input class="phone"> with a <button class="remove"> beside it; <p class="count"> says "N numbers". Numbers are required, so the form is invalid while one is empty.
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.