Manuel Putzu’s Post

Simple JavaScript challenge 🧑💻 What will be the output of this code? for ( var i = 0; i < 3; i++ ) {   setTimeout( () => {     console.log( i );   }, 0 ); } What's your answer? And why? #JavaScript #WebDevelopment #Frontend

A highly practical article on building bulletproof React components. I know that it sounds trivial but there are some good tips. Give it a read https://lnkd.in/dNqCsk65 #React #JavaScript

🤔 How do you decide between using a 𝗦𝗲𝘁 or an 𝗮𝗿𝗿𝗮𝘆 in #JavaScript? Recently I realized that I often reach for arrays by default, even in cases where a Set would be a better fit: when I only care about unique values and fast lookups, not about order. But in many everyday cases with small collections, arrays are still perfectly fine and often more readable. I’m currently trying to be more intentional: if I think “collection of unique things”, I reach for Set; if I need order, duplicates or array utilities, I stick with arrays. How do you handle this in your projects? #JavaScript #TypeScript #CleanCodeSolutions #WebDevelopment #Frontend

100 identical requests. 1 expensive DB call! I wrote about request collapsing and how to implement it in NestJS using an interceptor + decorator. https://lnkd.in/dJZK859c #javascript #nestjs #requestsandlimits

querySelector vs querySelectorAll – I learned this the hard way 🤦🏻 Just wasted 2 hours because my code only worked on the first button. All the others? Dead. Turns out querySelector() literally does what it says—it queries for ONE selector. I needed querySelectorAll() to grab all the buttons, then loop through them. Sometimes the answer is right there in the name and you still miss it 🤦🏻 #JavaScript #WebDevelopment #100DaysOfCode #LearningInPublic

Learning JavaScript: Loading Images with Ajax request Make a GET request Handle blob responses Display the image dynamically in the browser Small steps, but steady progress toward becoming a better web developer 💪 Always learning, always building. #JavaScript #WebDevelopment #LearningByDoing #Frontend #CodingJourney

🧩 JavaScript Output-Based Question (this + setTimeout) ❓ What will be the output? 👉 Comment your answer below (Don’t run the code ❌) Output: undefined 🧠 Why this output comes? (Step-by-Step) 1️⃣ print() is called as a method obj.print(); So inside print, this correctly refers to obj. 2️⃣ But inside setTimeout… setTimeout(function () { console.log(this.name); }, 0); The callback is a regular function, not a method of obj. When it executes: • this does NOT refer to obj • In non-strict mode → this points to the global object • In strict mode → this is undefined Either way: this.name → undefined 3️⃣ The key mistake ❌ Assuming this is preserved automatically in async callbacks 🔑 Key Takeaways ✔️ this depends on how a function is called ✔️ setTimeout callbacks lose object context ✔️ Use arrow functions or .bind() to fix this ✔️ This bug appears frequently in real projects #JavaScript #ThisKeyword #AsyncJavaScript #setTimeout #InterviewQuestions #FrontendDeveloper #MERNStack #ReactJS

JavaScript keeps surprising 😅 Every time it’s the same: “I thought I knew JS… until I saw this.” Inside the PDF: - weird-looking behavior - step-by-step breakdown - a clear explanation of what’s actually happening under the hood If this format is useful, let me know with a reaction or a comment — it really helps 🙌 PDF is attached below 👇 #javascript #jswtf #frontend #devlife

Struggling with JavaScript libraries re-initializing on Livewire updates? You're not alone! A common hurdle for many Livewire developers is integrating external JavaScript that modifies the DOM. When Livewire re-renders, it often overwrites these changes, breaking your UI or functionality. The secret cheat? Use `wire:ignore.self`! This directive tells Livewire to skip re-rendering the element itself during subsequent updates, preserving its state and any attached JS. Keep your dynamic content *inside* the ignored element for seamless updates. Master this tip to unlock smoother integrations with charts, sliders, or rich text editors! #LivewireTips #WebDevelopment #PHP #Laravel

Day 41/100 – An Important JavaScript Concept Many People Ignore Most beginners attach event listeners to every single element… But there’s a smarter and more efficient way. 📌 Topic: Event Delegation Instead of adding event listeners to multiple child elements, we add ONE listener to their parent and handle events using bubbling. ✅ Why it matters: • Better performance • Less memory usage • Handles dynamic elements easily Example: document.getElementById("list").addEventListener("click", function(e) { if (e.target.tagName === "LI") { console.log(e.target.textContent); } }); One listener. Many elements. Cleaner code. Understanding concepts like this makes JavaScript feel less magical and more logical. On to Day 42 🚀 #100DaysOfCode #JavaScript #WebDevelopment #LearningInPublic #Consistency #Frontend