TypeScript

Marking a parameter with a decorator in TypeScript

TypeScriptDecoratorsParameter Decoratorsadvanced

What this snippet does

Parameter decorators execute when the method is defined, providing the parameter index for metadata injection.

Expected output

Param 0 on run

Why practise typing this

Typing decorators 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

Browse all TypeScript snippets →