Frontend engineering · Languages
TypeScript
Also called: TS, TSX, Type annotations
JavaScript with type annotations added. It catches a lot of typos and data shape mistakes before the code even runs.
In detail
TypeScript is like adding a "form-filling standard" to JavaScript. You agree up front on what the data looks like, for example a user has a name (a string) and an age (a number). After that, if anyone passes the wrong thing or misspells a field name, the editor underlines it in red right away, instead of you finding out when the page breaks.
The file extensions are .ts or .tsx (for components with JSX). Browsers don't understand TypeScript directly, so the build step turns it into JavaScript first.
It's really useful for beginners coding with AI: when AI-generated code doesn't match your existing data structures, the type check complains right away. When you hit a type error, don't rush to let the AI paper over it with any. That's the same as turning off this safety net.
Developer infoTerm ID, DOM cues, match priority
- Term ID
eng-typescript- DOM selectors
- No DOM cues. This concept isn't detected directly on a page.
- Priority
- 1 · when several match at the same level, the higher priority wins
- Version
- v1 · updated Sep 29, 2026