← You've been deep-cloning objects with a JSON hack. `structuredClone` does it right.Quiz

structuredClone vs the JSON hack

Six questions on what structuredClone actually preserves versus JSON.parse(JSON.stringify(obj)) — Dates, Maps, Sets, circular references, class instances, and the transfer option.

questions6
pass mark70%
resultsat the end

No account needed. Answer all 6 questions, then see your score with every answer explained and a reference to the spec or MDN — pass and you can claim a certificate.