The useEffect Mental Model and Basics
Explore the useEffect hook to understand how React handles side effects after rendering, including data fetching and DOM interactions. Learn the render-commit-effect sequence to coordinate asynchronous behavior safely and build predictable React applications.
When we move beyond rendering static UI, we begin to interact with the outside world. We fetch data, update the DOM, start timers, and subscribe to events. These operations do not belong to the rendering process itself. They are side effects, and React treats them differently for a reason. To use useEffect correctly, we need a clear mental model of how React renders components and when effects are allowed to run.
What is a side effect?
A side effect is any operation that reaches ...