JavaScript typing practice

Type real JavaScript: arrow functions, template literals, destructuring, array methods like map, filter and reduce, classes with private fields, async/await with error handling, Node.js file reading, Express routes and tests.

Where JavaScript developers lose speed

Arrows =>, backticks and ${} in template literals, strict equality ===, optional chaining ?. and nested brackets. Klava shows which symbols cost you the most time and turns them into a drill.

Go further

Try the TypeScript and React sets, the endless code generator or editing practice.

More tests and practice