Checkpoint: Getting Started

Five questions on this section. Answer all of them, then see your score and why each answer is right or wrong.

A teammate clones the Watchlist repository and runs npm run dev. The terminal says vite: command not found. What should they do?

Vite shows “Adjacent JSX elements must be wrapped in an enclosing tag” for this component. Which fix is correct?

JSX

export default function App() {
  return (
    <h1>Watchlist</h1>
    <p>3 to watch</p>
  );
}

Wrap both elements in a fragment <>…</> or in a meaningful element such as <header>.
Remove the parentheses around the JSX.
Put a comma between the two elements.
Split the return into two return statements.

count is 0 and watched is true. What text does <p>{count} {watched}</p> show?

“0 true”
Nothing at all, because both values are skipped.
An error, because booleans are not valid children.
“0” (with a trailing space), because numbers render and booleans render nothing.

src/components/MovieCard.jsx contains export function MovieCard() { … } and nothing else. Which import works in App.jsx?

A colleague removes <StrictMode> from main.jsx because logs print twice in development. What is the best response?

Agree, because StrictMode makes the production app twice as slow.
Agree, because StrictMode is deprecated in React 19.
Keep it: the double run only happens in development and exists to expose impure rendering and missing cleanups early.
Keep it, but wrap each component in its own StrictMode as well.

5 questions unanswered