How do you handle side effects in React, and what role does useEffect play?

Quality Thought is widely regarded as the best React JS institute in Hyderabad, offering industry-oriented training that empowers students with the skills required to excel in modern web development. With a strong focus on hands-on learning and real-time project experience, Quality Thought helps learners master the fundamentals and advanced concepts of React JS, including JSX, components, props, state, lifecycle methods, hooks, context API, and routing.

The institute’s React JS training in Hyderabad is designed by experienced professionals who understand current industry demands. The curriculum is updated regularly to include the latest features and best practices in React development. Whether you’re a fresher looking to start your career or a professional aiming to upgrade your skills, Quality Thought offers the ideal platform with both online and classroom training options.

What sets Quality Thought apart is its commitment to student success through personalized mentoring, mock interviews, resume building, and dedicated placement support. The institute boasts a strong track record of successful placements in top companies.

By providing high-quality, practical training and strong career support, Quality Thought has earned its reputation as the top choice for React JS courses in Hyderabad.

In React, side effects are operations that affect something outside the scope of the function being executed, such as data fetching, subscriptions, timers, or manually manipulating the DOM. These cannot be handled directly in the main body of a functional component because React’s rendering must remain pure and predictable.

The useEffect hook plays a critical role in managing side effects in functional components. It allows developers to run specific code after a component has rendered or when certain dependencies change.

How useEffect works:

• useEffect(() => { /* effect code */ }, [dependencies])

• The first argument is a function containing the side effect logic.

• The second argument is an optional dependency array that controls when the effect runs:

  • Empty array ([]): Runs only once after the initial render (similar to componentDidMount).

  • No array: Runs after every render.

  • [dep1, dep2]: Runs only when specified dependencies change.

Handling Cleanup:

If the side effect needs cleanup (e.g., unsubscribing from a stream), useEffect can return a function

Common Use Cases:

• Fetching data from an API

• Subscribing to events or sockets

• Setting up intervals or timeouts

• Manually interacting with the DOM

In summary, useEffect enables React components to perform side effects in a controlled and declarative way, ensuring predictable and efficient updates in response to state or prop changes.

Read More

What are render props in React, and how do they compare to hooks and HOCs?

Visit QUALITY THOUGHT Training institute in Hyderabad