Learn how to use the useEffect Hook in functional components.

The useEffect Hook is used to perform side effects in a React Native’s functional component. Examples of side effects include fetching data from an external API, manipulating the DOM, and adding timers. The useEffect Hook runs after the first render of the component and after every update to the component.

Note: React Native’s components are pure functions, i.e., they give the same output for similar inputs every time. Side effects refer to interacting with the outside world and performing certain actions that may or may not return the same output for similar inputs every time.


To implement and use the useEffect Hook, we first have to import it from the react library.

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