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React Academy · Lesson

Common Pitfalls: Stale Closures & Missing Deps

Avoid stale closures and missing dependencies; learn safe patterns to read the latest values inside effects and timers.

Pitfalls overview

Goal: Spot and fix two common issues: stale closures (effect sees old values) and missing deps (effect does not re-run when it should).

Stale closure concept

A stale closure happens when a function (timer/listener) captures an old value from a previous render.

  • Effect doesn’t see latest state
  • Timer increments wrong

All lessons in this course

  1. Effects vs Render, Dependencies & Cleanup
  2. Common Pitfalls: Stale Closures & Missing Deps
  3. Fetching Basics in Effects (Abort & Cleanup)
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