Watching Values
Conditional Fields
Change the answers and watch fields appear and disappear. When a field unmounts its value is removed, so hidden fields never leak into the submitted values.
What this shows
useFieldWatch subscribes small components to the answers that control follow-up questions, so the rest of the form doesn't re-render.
When a field unmounts its edits are discarded, so hidden answers never reach onSubmit. See Core Concepts.