The useEffect Hook

In any application, certain actions or “side effects” need to occur outside the regular rendering cycle. In the context of React and programming in general, side effects refer to operations or actions performed by a function that interact with or modify something outside the function's scope, or affect the application in ways that are not purely computational. Examples include fetching data from an API, updating the DOM, or setting up timers.

In React, the useEffect hook allows us to handle these side effects in functional components without relying on component's lifecycle methods. This makes managing external interactions and cleanup tasks much more intuitive.

Understanding useEffect

The useEffect hook is used for performing side effects in our components. It runs after the component renders and can optionally re-run when specific values (called dependencies) change.

What are dependencies?

Dependencies are the values or state variables that, when changed, trigger the re-execution of the effect function provided to useEffect. These values are listed in an array as the second parameter of useEffect.

• Line 1: Imports useState and useEffect hooks.

• Line 4: Initializes a count state variable with 0. ...