Answer
React re-renders only when the state updater function is called. Direct mutation does not notify React.
Quick Answer
React tracks state through its setter function, not the object itself. When you do state.count = 5 directly, React never knows anything changed and doesn't schedule a re-render. You must call setState(newValue) — that's what signals React to diff the new state against the old and update the UI.
S
SugharaIQ Editorial Team
Verified Answer
This answer has been peer-reviewed by industry experts holding senior engineering roles to ensure technical accuracy and relevance for modern interview standards.
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Source: SugharaIQ