useMemo: Preserving Computation Results
- The `useMemo` hook is used to memoize the result of expensive calculations within functional components.
- It takes a function and an array of dependencies as arguments.
- The hook will only recompute the memoized value when one of the dependencies has changed.
- It is useful for optimizing calculations, complex computations, or expensive operations to avoid unnecessary re-renders.
Example: Below is an example of useMemo hook.
Javascript
import React, { useMemo } from 'react' ; const MyComponent = ({ list }) => { const filteredList = useMemo(() => { return list.filter(item => item.value > 10); }, [list]); return ( <ul> {filteredList.map(item => ( <li key={item.id}>{item.name}</li> ))} </ul> ); }; export default MyComponent; |
Optimizing Performance with useMemo and useCallback Hooks
In React applications, optimizing performance is crucial for ensuring smooth user experiences, especially in components with complex computations or frequent re-renders. Two hooks provided by React, useMemo, and useCallback, offer efficient ways to achieve performance improvements by memoizing values and callback functions, respectively.
Table of Content
- Understanding the Need for Optimization
- Determining When to Utilize These Hooks
- useMemo: Preserving Computation Results
- useCallback: Memoizing Functions
- How useCallback works?
- Preventing Unnecessary Child Component Rerenders
- Benefits of useMemo an useCallback Hooks
- Conclusion