← addDays() Mutated a Date Three Components Away From Where I Called ItQuiz
Date's mutation trap, and what Temporal fixes
Check what you took from the post: why a Date-mutating helper corrupts data its caller never expected to change, what Temporal's immutability actually guarantees, and where Temporal stands in real browsers today.
questions7
pass mark70%
resultsat the end
No account needed. Answer all 7 questions, then see your score with every answer explained and a reference to the spec or MDN — pass and you can claim a certificate.