Type Signature · #80 · 2026-06-23
What happens if you call `first([])`?
TypeScript ·Difficulty 2/3
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.
function first<T>(arr: [T, ...T[]]): T {
return arr[0];
}
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Press 1 through 4, or tap a numbered choice, to answer. Back to hub