TypeScript

Defining a string or null union in TypeScript

TypeScriptAdvanced TypesNullable Typesbeginner

What this snippet does

Nullable types explicitly mark where absence is a valid value, preventing null reference errors.

Expected output

null

Why practise typing this

Typing advanced 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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