Stale Closure

Definitions

1. A bug in JavaScript (especially React hooks) where a closure captures a variable by reference at a particular point in time and continues to use that now-outdated value in subsequent executions, rather than the current value. This commonly occurs when a useEffect or event handler closes over a state variable but lacks it in its dependency array.

   In plain English: When a function remembers an old version of a value instead of the current one, causing it to work with outdated information.

   Example: "The counter shows 0 every time because the setInterval callback has a stale closure over the initial count value — add count to the useEffect dependency array."

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