Adding Side Effects with useEffect()
Explore how the useEffect Hook replaces traditional React lifecycle methods to manage side effects such as API calls and event handling. Understand the function's parameters, cleanup mechanics, and dependency arrays to simplify component behavior and enhance state management in functional React components.
useEffect() vs. lifecycle methods
The name of the useEffect() Hook derives from its intended usage: for side effects. In this
case, we mean loading data via an API, registering global events, or manipulating DOM
elements. The useEffect() Hook includes functionality that was previously found in the componentDidMount(), componentDidUpdate(), and componentWillUnmount() lifecycle
methods.
If you’re wondering whether all these lifecycle methods have now been replaced and been combined into a single Hook, you’re correct. Instead of using three methods, you only need to use a single Hook, which takes effect in similar places where the class component methods were previously used. The trick is to use particular function parameters and return values that are intended for the useEffect() Hook.