What Are the States of a Promise?
What are the states of a promise? How do then, catch and finally behave?
Answer out loud in under a minute: a definition, one concrete example, and one pitfall or trade-off.
Hints
Hint 1
Say what "settled is final" means for a second resolve, and when a handler on an already-settled promise runs.
Solution
Show the approach
Answer
Pending, then fulfilled or rejected, and settled is final: a later resolve or reject is ignored. then, catch and finally each return a new promise, which is what makes chaining work. Handlers always run as microtasks, never synchronously, even on an already-settled promise. finally sees neither the value nor the reason, and passes the original outcome through unless it throws.
Promise sequencing in code is Run Promises in Sequence.