TypeScript

Attempting string keyof on a tuple in TypeScript

TypeScriptBasic Typeskeyof with numbersadvanced

What this snippet does

Tuple indices are technically represented as string literals in TypeScript, but intersecting with 'string' can sometimes yield unexpected empty types depending on the context.

Expected output

0

Why practise typing this

Typing basic types code builds muscle memory for the symbols and indentation TypeScript uses most, which prose-based typing tests never cover. DevType measures your words per minute and accuracy on this snippet and tracks the individual characters you mistype, so later lessons can target them.

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