To simulate componentWillUnmount with useEffect

• Define a useEffect Hook: Start by using the useEffect Hook in your functional component.
• Inside useEffect: Implement the logic you want to execute when the component mounts.
• Return a Cleanup Function: To simulate componentWillUnmount, return a function from the useEffect. This returned function will be called when the component is about to unmount.
• Cleanup Logic: Inside the cleanup function, you can include any cleanup logic or perform actions needed before the component is unmounted.
• Depnedency Array: If you want the cleanup function to run only when the component unmounts (similar to componentWillUnmount), ensure that the dependency array is empty ([]) in the useEffect. This ensures the effect runs once when the component mounts and the cleanup runs when the component unmounts.
• To Avoid memory Leaking: Properly cleaning up resources in the cleanup function is key for preventing memory leaks. This is especially important when dealing with subscriptions, event listeners, or any long-lived resources.

To simulate componentWillUnmount using useEffect in a functional component, you can return a cleanup function inside the useEffect. This cleanup function will be executed when the component is unmounted.

Syntax of useEffect Hook:

useEffect(() => {
    // Your component did mount logic here
    return () => {
      // Your componentWillUnmount logic here
    };
}, []);