フリー問題

問題文

A legacy helper takes an error first callback. A team wants to await it. What is the appropriate step?

選択肢

1. Call the helper inside a loop and read the returned value once the loop finishes.
2. Mark the helper as async, and adding the keyword makes the engine convert the callback style into a promise automatically.
3. Wrap the helper in a function that returns a new promise and resolves or rejects it from inside the callback.
4. Await the helper directly, and await accepts any value and will wait for a callback based function.