TypeScript

Type assertion overriding the inferred type in TypeScript

TypeScriptVariables and DeclarationsType Assertionsbeginner

What this snippet does

Type assertions force the compiler to accept a type, which hides compile errors but causes runtime crashes if incorrect.

Expected output

TypeError: y.toFixed is not a function

Why practise typing this

Typing variables and declarations 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 →