Type Signature · #31 · 2026-05-05

What is the type of `a`?

TypeScript ·Difficulty 1/3

How to play

Read the TypeScript snippet and pick the correct type from four choices. Think about inference, narrowing, and utility types. Press 1–4 or click to answer.

async function f() {
  const [a, b] = await Promise.all([
    Promise.resolve(42),
    Promise.resolve('hello')
  ]);
  return a;
}

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Press 1 through 4, or tap a numbered choice, to answer. Back to hub