ref as a prop in React
React interview exercise on React 19, difficulty 2 of 3. Solve it in the editor beside a worked example; the tests run the moment you do.
Write TextField({ label, ref, ...rest }): a <label> with the text and an <input> that receives the ref and any other props. Then LoginForm: two TextFields (classes "user" and "pass") and a <button className="focus-user"> that focuses the first one through a ref the form owns.
Each exercise pairs a worked example with a twin problem to solve in a real editor; the tests run the moment you do. Progress is saved in your browser, and in your account if you sign in.