Mastering useEffect: A Step-by-Step Guide

📌 Exploring useEffectEvent - a fresh experimental React Hook worth knowing Ever struggled with useEffect re-running too often or working with outdated state values? Yeah, me too 😅 -> That’s exactly the problem the new experimental hook useEffectEvent is trying to solve. 🔴 When you use useEffect, you often face a trade-off: - If you include every state and prop in the dependency array -> the effect keeps re-running. - If you skip some -> you risk working with stale (old) values. - Neither feels great - 🟢 Enter useEffectEvent It lets you create a stable function that: -> always “sees” the latest values of your state and props, -> but doesn’t cause the effect to re-run when those values change. Basically, it separates “what happens” from “when it happens”. ⚠️ A quick note: useEffectEvent is still experimental — it might change in future React versions, so I’d keep it for experiments, not production (yet). 💭 My takeaway: This hook feels like a solid step toward cleaner, more predictable effects. Less dependency juggling, fewer re-renders, and more focus on logic. 👉 Have you already tried useEffectEvent? Curious to hear what you think about it 👇 #React #Frontend #JavaScript #LearningJourney

🚀 Back to Basics – Day 19: Debugging React Performance Like a Pro 🔥 In the last post, we explored rendering bottlenecks — understanding why components re-render and how to control them. Today, let’s move from theory to practice: how to find and fix these slowdowns in real React projects. 🧩 ✨ Why This Matters You can’t optimize what you can’t measure. Profiling reveals where time and memory are really going — because sometimes, the “slow” part isn’t where you think. 👀 ⚙️ 1️⃣ React DevTools Profiler – Your First Stop React’s built-in Profiler shows which components re-render, how long they took, and why. ✅ Open DevTools → “Profiler” tab ✅ Record interactions like scrolls or clicks ✅ Identify components with long render times 💡 Tip: Highlight frequent re-renders — they often signal missing React.memo() or unnecessary state updates. ⚙️ 2️⃣ Flame Graphs – Visualizing the Problem Flame graphs (in Chrome or React Profiler) help you see performance hotspots. Each bar = function or component; width = time taken. ✅ Look for wide or repeating bars — those are your bottlenecks. ✅ Combine with “why did this render?” tools to pinpoint causes. ⚙️ 3️⃣ Real-World Fixes 🔹 Split heavy components using dynamic imports (React.lazy) 🔹 Cache computed data with useMemo() 🔹 Limit re-renders with keys, pure components, and controlled props Bonus: Audit with Lighthouse and Performance Tab in Chrome DevTools for end-to-end metrics (TTI, FID, CLS). 💡 Takeaway Optimizing React isn’t about guessing — it’s about measuring. Once you can profile, visualize, and tune your components, you’re not just building — you’re engineering performance. ⚙️ 👉 Tomorrow – Day 20: We’ll wrap up our performance chapter with Rendering Optimization Strategies for Modern Frameworks — from React to Next.js, and how hydration and server rendering affect speed. 🚀 #BackToBasics #React #JavaScript #Frontend #WebPerformance #Optimization #Rendering #Profiling #LearningInPublic #CodingJourney #AdvancedJavaScript

🚀 Mastering useEffect in React If you’ve ever wondered why your component keeps re-rendering, or how to handle side effects properly, useEffect is your best friend (when used right!). 🧠 What is useEffect? useEffect lets you perform side effects in functional components — like fetching data, updating the DOM, or setting up event listeners. 💡 Basic Syntax useEffect(() => { // Side effect logic here return () => { // Cleanup (optional) }; }, [dependencies]); ⚙️ Dependency Array Explained [] → runs only once (on mount) [variable] → runs when variable changes (no array) → runs after every render 🧩 Common Use Cases ✅ Fetching data from an API ✅ Subscribing / unsubscribing to events ✅ Managing timers or intervals ✅ Syncing state with localStorage ⚠️ Avoid These Mistakes ❌ Forgetting the dependency array ❌ Updating state inside useEffect without proper dependencies (infinite loop alert 🚨) ❌ Not cleaning up event listeners or intervals 🌱 Pro Tip Always think of useEffect as a lifecycle tool — it replaces componentDidMount, componentDidUpdate, and componentWillUnmount from class components. #ReactJS #FrontendDevelopment #WebDevelopment #JavaScript #ReactHooks #useEffect

🚀 How to Write a Dynamic Table Using DominatorJS! We’re excited to share a ready-to-run source code example showing how to create a dynamic table listing all DRC presidents from independence to now entirely with DominatorJS. 🎥 Watch the tutorial video 💻 Download the source code: ⬇️ Get it here https://lnkd.in/dg5V3PZr In this example, you’ll learn how to: ✅ Build tables dynamically from a JavaScript array ✅ Include images, dates, and text with object-based DOM creation ✅ Style tables directly using DominatorJS objects 💡 Why this matters: DominatorJS makes DOM manipulation fast, simple, and beginner-friendly. Perfect for experimenting with real projects, building interactive UIs, and leveling up your JavaScript skills. 🔥 Get hands-on now: Run the code immediately Modify it to create your own dynamic tables Share your results in the comments we’d love to see your creations! #DominatorJS #JavaScript #DynamicTable #congodevelopers #LearnToCode #OpenSource #WebDev 

JavaScript Promise.race() — When Speed Matters! Sometimes, you don’t need all async tasks to finish — you just want the fastest one’s result That’s where Promise.race() comes in! 💡 Definition: Promise.race() takes an array of promises and returns the result of the first one that settles (either resolved or rejected). 🧩 Example: const fast = new Promise((resolve) => setTimeout(() => resolve("🚀 Fast task completed!"), 1000) ); const slow = new Promise((resolve) => setTimeout(() => resolve("🐢 Slow task completed!"), 3000) ); Promise.race([fast, slow]) .then((result) => console.log("Winner:", result)) .catch((error) => console.error("Error:", error)); ✅ Output: Winner: 🚀 Fast task completed! Even though the slow promise finishes later, the first one decides the result. Why Use It? ✅ Get quick responses from multiple sources ✅ Useful in timeout or failover situations ✅ Improves user experience by reacting faster 🔖 #JavaScript #PromiseRace #AsyncProgramming #WebDevelopment #Frontend #JSConcepts #CodingTips #100DaysOfCode #KishoreLearnsJS #WebDevCommunity #DeveloperJourney #AsyncAwait

Github: https://lnkd.in/gXq_-4mp 🔥 Project 2/20 — Sticky Header + Scroll Reveal ✨ Today we’re leveling up UI fundamentals. No React, no Tailwind — just pure HTML, CSS & JavaScript flexing its muscles. This sticky navbar transforms as you scroll, paired with silky smooth reveal animations using the Intersection Observer API. Modern devs love frameworks. Great devs master fundamentals first. And we’re building the foundation brick by brick — one clean UI at a time. Because good code isn’t just written — it’s crafted. 📌 Concepts: ✅ Scroll events ✅ Intersection Observer ✅ DOM manipulation ✅ UI animations 🔗 GitHub repo in bio Follow along — 18 more fire projects coming. We’re not coding… we're forging skills. ⚔️🔥 #javascript #webdevelopment #frontend #htmlcssjavascript  #uiuxdesign #frontendprojects #stickyheader #scrollanimation  #vanillajs #cssanimations #intersectionobserver  #learningtocode #webdevjourney #codingreels #codetutorial  #githubproject #frontenddeveloper #webdesign  #softwareengineer #programminglife #buildinpublic  #100daysofcode #devcommunity #codewithme #codeweaver

📅 Day 4: Unlocking Component Lifecycle with useEffect Today, I took the plunge into side effects in React, and it's completely changed how I think about data fetching and manual DOM updates! I spent the day mastering the useEffect hook, which lets functional components "do things" after rendering. 🧠 Key Takeaways: Purpose: Learned that useEffect is essentially the modern way to handle logic that used to live in componentDidMount, componentDidUpdate, and componentWillUnmount. Dependency Array: Understood how the dependency array ([]) controls when the effect runs (every render, once on mount, or only when certain variables change). This is the key to preventing infinite loops! 💡 Cleanup: Practiced returning a function from useEffect for cleanup (e.g., clearing timers or removing event listeners) to prevent memory leaks. 🛠️ I implemented useEffect to: Fetch a list of posts/data from an external API when the component first loads. Update the document title based on a user interaction. Next up, I'll combine my knowledge of useEffect with React Router to load dynamic content on different pages! #ReactJS #useEffect #Hooks #WebDevelopment #100DaysOfCode #Frontend #JavaScript

useEffect finally made sense when I realized it's just "do something after rendering" 💡 Spent weeks confused by useEffect. Docs talked about side effects, lifecycle methods, synchronization. Too abstract. Then someone explained it simply: React renders your component. Displays it on screen. THEN runs useEffect. That's it. Need to fetch data after component appears? useEffect. Need to update document title? useEffect. Need to start a timer? useEffect. Anything that happens AFTER the initial render goes in useEffect. The dependency array controls WHEN it runs again: Empty array? Only after first render. Never again. Has values? Runs after render IF those values changed since last time. No array? Runs after EVERY render (rarely what you want). Cleanup is just "undo what you did": Added event listener? Remove it in cleanup. Started timer? Clear it in cleanup. Opened connection? Close it in cleanup. My biggest useEffect mistakes: Putting fetch directly in component body instead of useEffect. Infinite loops. Forgetting the dependency array. Infinite loops again. Not cleaning up timers. Memory leaks everywhere. Missing dependencies. Stale data showing on screen. Making useEffect async. React errors. This guide covers: What useEffect actually does (simple explanation) When to use it vs when not to Dependency arrays without the confusion Cleanup functions explained clearly Every mistake I made learning this useEffect isn't scary once you understand: render first, effects second. #ReactJS #WebDevelopment #JavaScript #useEffect #ReactHooks #LearningReact

GitHub : https://lnkd.in/gvjUhzmC 🔥 Day 1 of 20 JavaScript Micro-Projects 👨💻 Today we’re building a fully responsive navbar using only HTML, CSS & Vanilla JS — no frameworks, no shortcuts, just raw frontend grind. Modern UI, glass effect, smooth animations, mobile hamburger toggle — this is how real devs learn UI fundamentals. Because before React, before frameworks, before hype… there were skills. We build foundations. We sharpen fundamentals. We rise. 💡 Project #1: Responsive Navbar 🧠 Concepts: DOM manipulation, class toggling, mobile-first layout 🔗 GitHub repo in bio ⚡ Follow for 19 more fire projects Let’s craft greatness — one line of code at a time. 🚀💙 #javascript #frontend #webdevelopment #htmlcssjavascript  #javascriptprojects #frontendprojects #vanillajs #webdev  #cssdesign #responsivewebdesign #coderlife #uiuxdesign  #codingreels #learnjavascript #frontenddeveloper  #programminglife #javascriptreels #100daysofcode  #webdevcommunity #codetutorial #buildinpublic  #softwareengineering #techcontent #devcommunity  #codeweaver

🚀 Stop Writing Long DOM Code! DominatorJS Makes It Effortless 🎉 I just shared a new example: “Create a Dynamic Dropdown with DominatorJS” Here’s what you’ll see in action: ✅ Build a dynamic dropdown from a JavaScript array ✅ Attach event listeners directly in the configuration object ✅ Simplify DOM manipulation without messy code 💡 DominatorJS empowers developers — beginners or pros — to create interactive UI elements faster and smarter. 🎥 Watch the demo in this short video 👇 (screenshot/video attached) …and download the full source code to try it yourself here: https://lnkd.in/dANZEZdg #DominatorJS #WebDevelopment #CongoDevelopers #JavaScript #Frontend #LearningByDoing #OpenSource #CodeSmart #Productivity