Boost React Performance with Lazy Loading

🚀 Day 5/30 – State in React One of the most important concepts 🔥 Today I learned: ✅ State stores dynamic data inside a component → It allows components to manage and update their own data ✅ When state changes → React re-renders the UI → React automatically updates only the changed parts (efficient rendering ⚡) ✅ Managed using useState hook → The most commonly used hook in functional components ✅ State updates are asynchronous → React batches updates for better performance 💻 Example: import { useState } from "react"; function Counter() { const [count, setCount] = useState(0); const handleClick = () => { setCount(prev => prev + 1); // safe update }; return ( <div> <h2>Count: {count}</h2> <button onClick={handleClick}>Increment</button> </div> ); } 🔥 Key Takeaway: State is what makes React components interactive, dynamic, and responsive to user actions. #React #State #FrontendDevelopment #JavaScript #WebDev #CodingJourney #LearnInPublic

🚨 I used index as key in React… …and spent HOURS debugging something that made no sense. Everything looked fine at first. Until I: → deleted an item → reordered the list 💥 Suddenly: ❌ Wrong data was displayed ❌ UI behaved randomly ❌ Bugs I couldn’t explain I kept checking my logic. Turns out… the bug wasn’t my logic. 👉 It was THIS: {data.map((item, index) => ( <div key={index}>{item.name}</div> ))}💡 Problem: React uses keys to track identity. When you use index: → identity = position ❌ → not the actual item So when the list changes… React gets confused 😵 ✅ Fix: {data.map((item) => ( <div key={item.id}>{item.name}</div> ))}👉 Stable key = stable UI 💡 Lesson: If your UI feels “random”… check your keys before your logic. Follow me for more such tips ✍️ 👨💻 #ReactJS #Frontend #JavaScript #SoftwareEngineering

Most React tutorials are still teaching 2020 patterns. In 2026, the ecosystem has shifted dramatically: React 19 is stable, the compiler handles most memoization automatically, and useEffect should be a last resort — not your go-to for data fetching, derived state, or event responses. This guide walks you from project setup to production-ready patterns, with a cheat sheet you can bookmark. #react #web #frontend #next #frontend #performance #javascript #tips #typescript #nextjs

A lot of people constantly ask me what React Hooks actually are, and the best way to think about Hooks and JavaScript concepts in general is to look at what problem they were trying to fix. For example, before React Hooks, people would create a Container Component and a Presentational Component. The Container Component would retrieve data, like making a fetch request, and then pass that data down to the Presentational Component, which was usually a pure function that returned some UI, like a div with styling, and accepted that data as props. This pattern helped create a standard for how data was retrieved in React and enforced separation of concerns, but it ended up being too boilerplate heavy for most people. So Hooks were introduced to let us hook into components directly, allowing us to load data as a side effect inside a function while still maintaining separation of concerns without needing extra components. #ReactJs #JavaScript #JavaScriptHooks

Why do we specifically pass 'props' into 'super(props)' in a React component constructor? It is one of those things many developers do out of habit without realizing the actual mechanism behind it. While calling 'super()' is a JavaScript requirement to initialize the 'this' keyword, passing 'props' is a very specific React requirement for the constructor phase. The reason is simple: visibility. When you call 'super(props)', you are telling the parent 'React.Component' class to initialize 'this.props' for you immediately. If you only call 'super()' without the argument, 'this.props' will be undefined inside the constructor. React eventually assigns props to the instance anyway, but that happens after the constructor has finished running. If your logic requires you to access a property or compute a state based on a prop right inside the constructor, forgetting the 'props' argument will crash your logic. You would be trying to read from a variable that hasn't been wired up to the instance yet. Even though modern React code bases have shifted to Functional Components where this ceremony is gone, the underlying logic of when data becomes available to an instance is a core part of the library’s history. It is a small detail that perfectly illustrates how React works under the hood. #ReactJS #Javascript #SoftwareEngineering #FrontendDevelopment #WebDev #CodingTips

React is finally getting a built-in useForm hook… and it’s a big shift Right now, every project: 🔹 Formik 🔹 React Hook Form 🔹 Zod + custom logic More setup. More dependencies. More bundle size. Now React is bringing it into core 🔹 Validation 🔹 Form state 🔹 Submission 🔹 Error handling All built-in. No extra libraries. We’ve seen this pattern before: → Data fetching → now simpler patterns → Routing → built into frameworks → Memoization → handled by React Compiler React continues to absorb what we used to depend on. That’s not a problem - that’s growth What this means now: 🔹 Don’t over-engineer forms 🔹 Keep it simple 🔹 Focus on fundamentals (controlled vs uncontrolled) Libraries change. Basics don’t. Still using Formik or React Hook Form? 👇 #ReactJS #WebDevelopment #FullStackDeveloper #Frontend #JavaScript

You wrapped your component in React.memo… but it still re-renders 🤔 I ran into this more times than I’d like to admit. Everything looks correct. You’re using React.memo. Props don’t seem to change. But the component still re-renders on every parent update. Here’s a simple example: const List = React.memo(({ items }) => { console.log('List render'); return items.map(item => ( <div key={item.id}>{item.name}</div> )); }); function App() { const [count, setCount] = React.useState(0); const items = [{ id: 1, name: 'A' }]; return ( <> <button onClick={() => setCount(count + 1)}> Click </button> <List items={items} /> </> ); } When you click the button the List still re-renders. At first glance, it feels wrong. The data didn’t change… so why did React re-render? The reason is subtle but important: every render creates a new array. So even though the content is the same, the reference is different. [] !== [] And React.memo only does a shallow comparison. So from React’s perspective, the prop did change. One simple fix: const items = React.useMemo(() => [ { id: 1, name: 'A' } ], []); Now the reference stays stable and memoization actually works. Takeaway React.memo is not magic. It only helps if the props you pass are stable. If you create new objects or functions on every render, you’re effectively disabling it without realizing it. This is one of those bugs that doesn’t throw errors… but quietly hurts performance. Have you ever debugged something like this? 👀 #reactjs #javascript #frontend #webdevelopment #performance #reactperformance #softwareengineering #programming #coding #webdev #react #typescript

React vs. Redux vs. Redux Toolkit: Which should you use? "Do I need Redux?" is still one of the most common questions in frontend development. State management can be overwhelming, but understanding the evolution of these tools makes the choice much clearer. Here is a straightforward breakdown of the big three: 1️⃣ React State & Context (The Foundation) React’s built-in hooks (useState, useReducer, useContext) are often all you need. The Good: Zero extra dependencies. It is perfect for local component state (like form inputs or UI toggles) and low-frequency global state (like user themes or auth status). The Bad: Relying purely on Context for high-frequency, complex global state can lead to unnecessary re-renders and messy prop-drilling. 2️⃣ Classic Redux (The Legacy Heavyweight) Redux revolutionized how we handle global state by introducing a single, predictable source of truth. The Good: Unmatched predictability and incredible developer tools (time-travel debugging is magic). The Bad: The boilerplate. Writing separate files for actions, action types, and reducers slows down development and frustrates teams. 3️⃣ Redux Toolkit / RTK (The Modern Standard) Redux Toolkit is not a replacement for Redux; it is the official, modern way to write it. It takes everything great about Redux and strips away the pain points. The Good: It drastically reduces boilerplate. Features like createSlice automatically generate your actions and reducers. It includes Immer under the hood (allowing you to write simpler, "mutating" logic that updates state immutably), and it ships with RTK Query for incredibly efficient data fetching and caching. The Verdict: If you are starting a new project that genuinely needs Redux, RTK is the only way you should be writing it. 💡 My Rule of Thumb: Start simple. Build with React's built-in state. When your state starts feeling tangled, difficult to track, or requires passing props through five layers of components (Prop Drilling)—it's time to bring in Redux Toolkit. How is your team handling state management these days? Are you firmly on team RTK, or have you pivoted to lighter alternatives like Zustand or Jotai? Let's discuss in the comments! 👇 #ReactJS #Redux #WebDevelopment #Frontend #SoftwareEngineering #JavaScript

⚛️ React Tip: When Should You Use useCallback? While working on React applications, one common performance issue developers face is unnecessary component re-renders. One hook that often comes up in this discussion is useCallback. But many developers (including me earlier) either overuse it or use it incorrectly. So here’s a simple way to understand it. 🔹 What does useCallback do? `useCallback` memoizes a function. This means React will reuse the same function instance unless its dependencies change. Example 👇 const handleClick = useCallback(() => { console.log("Button clicked"); }, []); Without `useCallback`, a new function is created every time the component re-renders. Most of the time this isn’t a problem. But it becomes important when passing functions to memoized child components. 🔹 Example scenario Imagine a parent component passing a function as a prop to a child component wrapped with `React.memo`. If the function reference changes on every render, the child component will also re-render unnecessarily. Using `useCallback` helps keep the function reference stable, preventing those extra renders. 🔹 When should you actually use it? ✅ When passing callbacks to memoized components ✅ When the function is a dependency in another hook ✅ When optimizing large component trees ⚠️ When NOT to use it: • For every function in your component • When there is no performance issue • Just because someone said it improves performance 💡 One important lesson I’ve learned: Optimization should be intentional, not automatic. React already does a lot of work under the hood. Use hooks like `useCallback` only when they actually solve a problem. Curious to hear from other developers 👇 Do you use `useCallback` often, or do you prefer optimizing only after profiling? #reactjs #frontenddevelopment #javascript #webdevelopment #reacthooks #softwareengineering #coding

Stop disabling the exhaustive-deps linter in your React Effects ⚛️. we all did the same dirty hack: // eslint-disable-next-line 👇. It is the most common frustrating scenario in React development: You write a useEffect to connect to a websocket or track an analytics event. Inside that effect, you need to read the current value of a state variable—like a shopping cart count or a UI theme. But the moment you read that state, the React linter screams at you to add it to the dependency array. If you add it, your effect re-runs every time the state changes (destroying your websocket connection!). If you don't add it, your build fails. So, we all did the same dirty hack: // eslint-disable-next-line. React finally solves this permanently with useEffectEvent. ❌ The Legacy Way (eslint-disable): Forces you to break the rules of React. Creates a massive risk for stale closures and hidden bugs. Makes your code harder to maintain and review. ✅ The Modern Way (useEffectEvent): Extracts your "event" logic cleanly out of your "lifecycle" logic! • Always Fresh: It guarantees your callback will always read the absolute latest props and state. • Non-Reactive: It is intentionally ignored by the dependency array. It will never cause your useEffect to re-run. • Clean Code: You can finally turn your linter rules back on and trust your dependencies again. The Shift: We are moving away from fighting the framework and using dedicated primitives to separate reactive synchronization from non-reactive events. #ReactJS #React19 #WebDevelopment #Frontend #JavaScript #CleanCode #SoftwareEngineering #TechTips #WebDev #WebPerf #Tips #DevTips #ReactTips #FrontendDeveloper #DeveloperTips