React setState Batching Explained

Added: 2026-05-16

[00:00:00]Interview question, >> [music] >> quick developer challenge. In React, which will cause two renders? Calling set state twice in the same event handler >> [music] >> or batching them into one object update?

[00:00:11]Think carefully, pause and try yourself.

[00:00:13][music] Answer. In modern React with automatic batching, both set state calls [music] in the same event handler are batched into one render, so only one render happens. [music] Short explanation. React batches state updates during event handlers, so separate set state calls combine into one update.

[00:00:32]Explicit asynchronous boundaries can break batching.

[00:00:35]>> [music] >> Follow for more developer questions.