useEffect Explained: 8 Common Mistakes and How to Fix Them
8 useEffect mistakes almost every React dev makes — stale closures, missing cleanup, infinite loops, race conditions — fixed with 8 live demos.
useEffect Explained: 8 Common Mistakes and How to Fix Them
useEffect Explained: 8 Common Mistakes and How to Fix Them Almost every confusing useEffect bug comes from the same handful of misunderstandings, repeated in different clothes: treating the dependency array as optional, closing over a value that's already gone stale, forgetting that objects are compared by reference, or reaching for an effect when the answer was a plain calculation or an event handler all along. None of these are edge cases — they're the ones nearly every React developer hits in their first few months, and several of them ship into production because nothing crashes when they're wrong; the UI just quietly does the incorrect thing. The 8 demos below are all live and interactive, and every one that has a "broken" side keeps it running right next to the fix so you can watch the actual difference in behavior, not just read about it. Every embed also has a Fork & Edit button that opens the exact snippet, already running, in My Code — FWD Tools' …
