Why JS Practice exists

Most JavaScript tutorials and interview lists are written for people becoming frontend or React developers. QA engineers, SDETs, and testers who write Playwright, Cypress, or Selenium scripts get the same interview questions — closures, the event loop, promises, JSON — but almost no material explains them in that language.

JS Practice is one person's attempt to fix that: an original 50+ chapter tutorial, 240+ in-browser coding challenges, and 300+ interview questions and answers, all written around the examples a tester actually runs into — flaky assertions caused by the event loop, fetch without await, JSON parsing surprises, and closures inside a loop of test cases.

Everything on the site is original content: no scraped questions, no copied explanations. Every challenge runs in the browser with real tests, so you find out immediately whether your answer actually works, not just whether it looks right.

Practicing every challenge, reading the tutorial, and drilling interview questions is free. A one-time Lifetime unlock (₹499, no subscription) adds solutions, AI hints, mock-interview scoring, and a downloadable interview PDF for people who want the extra edge before a real interview.

Questions, feedback, or a broken example? Email friend9831@gmail.com — every message gets read. There's also a contact page with team licensing and mock-review options.