Using key props incorrectly in .map() lists
Using key props incorrectly in .map() operations is a common React anti-pattern that can lead to performance issues, state bugs, and unexpected rendering behavior. Here’s how to properly handle keys….
Tag: React DevTools
Using unnecessary dependencies in useEffect
A common React performance issue occurs when useEffect dependencies are incorrectly specified, leading to: Core Principles 1. The Dependency Array Should Reflect All Reactive Values Every value used inside the….
Using useReducer but forgetting to return a new state in the reducer function
Forgetting to Return New State in useReducer A common mistake when using useReducer is mutating the existing state or forgetting to return a new state object from the reducer function,….
Accessing state immediately after setState() before it updates
A common React pitfall is trying to access an updated state value immediately after calling setState or the state setter from useState. This doesn’t work because state updates are asynchronous….
Using useState but forgetting to initialize it with a default value
Forgetting to Initialize useState with a Default Value A common React mistake is declaring state with useState but forgetting to provide an initial value, which can lead to undefined errors….
Using hooks inside class components
A fundamental limitation of React is that hooks cannot be used inside class components. This is a deliberate design choice by the React team, as hooks were created specifically for….
Forgetting to remove event listeners on unmount
Forgetting to Remove Event Listeners on Unmount in React A common memory leak issue in React occurs when event listeners aren’t properly cleaned up when components unmount. This can lead….
Not handling right-click (contextmenu) events properly
Properly Handling Right-Click (Context Menu) Events in React A common oversight in React applications is not properly handling right-click (contextmenu) events, which can lead to broken user experiences or security….
Using arrow functions inside JSX without memoization leading to re-renders
Arrow Functions in JSX Without Memoization A common React performance pitfall is using inline arrow functions in JSX without proper memoization, which can cause unnecessary re-renders of child components. The….
Debugging React Performance Issues with Flame Graphs
Flame graphs are powerful visualization tools that help identify performance bottlenecks in React applications. Here’s a comprehensive guide to using them effectively: Understanding Flame Graphs What They Show Key Patterns….