What this snippet does
Unlike 'any', 'unknown' requires type narrowing before you can call methods on it, preventing runtime crashes.
Expected output
Compile Error: 'u' is of type 'unknown'.
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.
More TypeScript practice
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- Pushing a wrong type to a typed arrayBasic Types · beginner