Can re-rendering create problem in react app. 🙄
Re-rendering can create problems in a React app, especially when it happens unnecessarily or too often. This can lead to performance issues such as slow UI updates and reduced app responsiveness.
Example of Unnecessary Re-rendering:
Imagine you have a React component that displays a counter and a button to increment the count. There's also another component that renders a header, but it doesn't depend on the counter. If the header component is re-rendered every time the counter changes, it would be unnecessary.
What happens: See Figure 1
The Header component doesn't need to re-render when the count state changes because it doesn't depend on the count.
However, since it's inside the Counter component, it will re-render every time the Counter re-renders due to state change.
Solution: See figure 2
You can prevent this by wrapping the Header component with React.memo, which tells React not to re-render Header unless its props change.
Unnecessary Re-rendering Output:
Every time you click the button, you'll see "Header is re-rendered" in the console, which indicates unnecessary re-rendering.
Now, when the button is clicked, only the Counter component will re-render, and the Header component will not, as long as its props stay the same.
Key Takeaway:
Unnecessary re-renders can slow down your app, especially if you have many components or complex UI. Using techniques like React.memo or optimizing state management can help improve performance.
#reactjs #reactlearners #frontend #fullstack #webdevelopement
Director of Engineering at Very Good Ventures | GDE for Firebase | GDG Montevideo Organizer | Software Architecture Professor at ORT University
6mohttps://firebase.blog/posts/2024/05/app-hosting-vs-hosting