JavaScript & TypeScript Typing Practice

Modern JS is symbol soup: =>, ?., ??, ${...}, spread dots, and generics. Build muscle memory on real snippets instead of fumbling them mid-thought.

What you'll be typing

const result = arr.map(x => x * 2); const { name, age } = user; const value = obj?.nested?.deep ?? fallback; useEffect(() => { return () => cleanup(); }, [dep]); // TODO: handle empty response from the API

Why JS deserves its own drills

• Arrow functions and chains — => dozens of times a day, plus .filter().map().reduce()
• Template literals — backticks and ${ live in awkward corners of the keyboard
• Destructuring and spread — { ...rest }, [a, b], defaults
• TypeScript syntax — generics, type annotations, interfaces
• Comments included — // and /* */ are real typing too

Prefer another language? Python, Go, Rust, or the programmer typing guide.