Why :key must be an id in Vue
Vue interview exercise on Patterns, 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.
Notes renders one Note (a child with its own draft input) per note and a remove button in each. It is keyed by the index, so removing the first note shifts every draft to the wrong note. Fix the key (and keep the rest working): removing emits through `remove`, and each row shows its label.
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.