Advanced JavaScript — Day 3: Timers and Intervals Today I studied one of the most practical topics in JavaScript — setTimeout() and setInterval(). These two functions are everywhere in real-world development. Loading spinners, progress bars, countdowns, auto-sliding carousels, real-time clocks — all of it runs on timers. And today I didn't just learn the theory. I built a working Progress Bar using setInterval() to prove I actually understood it. Here's the full breakdown 👇 📌 setTimeout() 📌 setInterval() 📌 clearInterval() — The Most Important Part 📌 The Progress Bar Project 📌 Why Timers Matter in JavaScript Day 3 of Advanced JavaScript — done. Every project I build makes the concepts stick just a little bit more. That's the whole point. Day 4 tomorrow... #AdvancedJavaScript #JavaScript #Timers #setInterval #setTimeout #100DaysOfCode #LearnInPublic #WebDevelopment #Frontend #CodingJourney #BuildInPublic #ProjectBased #TechLearning

🧠 JavaScript Concept: Hoisting Explained Hoisting is JavaScript's behavior of moving variable and function declarations to the top of their scope before execution. This is why we can sometimes use variables or functions before they are declared. Example: console.log(name); // undefined var name = "Arun"; Why undefined? Because JavaScript internally treats it like this: var name; console.log(name); name = "Arun"; 🔹 Important Points: • "var" is hoisted and initialized with "undefined" • Function declarations are fully hoisted • "let" and "const" are hoisted but stay in the Temporal Dead Zone (TDZ) ⚠️ Accessing "let" or "const" before declaration will throw an error. 📌 Best Practice: Avoid relying on hoisting — always declare variables at the top for better readability. #javascript #frontenddevelopment #reactjs #webdevelopment #coding

Today I practiced the difference between map(), filter(), and forEach() in JavaScript. map() creates a new array by transforming each element of the original array. filter() creates a new array with elements that satisfy a specific condition. forEach() simply runs a function for each element and does not return a new array. Understanding these methods makes working with arrays much easier and cleaner. #JavaScript #WebDevelopment #ArrayMethods #LearningJourney

🚀 Prototypal Inheritance (JavaScript) JavaScript uses prototypal inheritance, a mechanism where objects inherit properties and methods from other objects. Every object has a prototype, which is another object. When a property is accessed on an object, JavaScript first checks if the object itself has the property. If not, it looks up the prototype chain until the property is found or the end of the chain is reached. This allows for code reuse and creating hierarchies of objects. Understanding prototypes is essential for building complex object-oriented applications in JavaScript. The `__proto__` property (deprecated but still often seen) and the `Object.getPrototypeOf()` method are used to access an object's prototype. #JavaScript #WebDev #Frontend #JS #professional #career #development

PEP TASK-6 🚀 Just built a Countdown Timer using JavaScript This project focuses purely on the power of JavaScript to handle real-time updates and dynamic behavior. 🔹 What I implemented: • Real-time countdown logic using JavaScript • Time calculations (days, hours, minutes, seconds) • Automatic UI updates using DOM manipulation • Efficient interval handling with setInterval() Through this project, I explored how JavaScript can be used to build interactive, time-based features without relying on external libraries. 💻 Check it out here: 👉 https://lnkd.in/ghEA3jH8 Feedback and suggestions are welcome! 🙌 #JavaScript #WebDevelopment #Frontend #Coding #StudentDeveloper #Projects

Assalam o Alaikum, JavaScript Lesson 27: Default Parameters, Optional Chaining & Nullish Coalescing. This lesson covers safer, cleaner JavaScript patterns: default function values, safe access to nested properties with optional chaining (?.), and better fallbacks with nullish coalescing (??) instead of ||. I also show how to combine them in real-world code with user/theme examples. Watch the lesson: https://lnkd.in/dG2KSTgs #JavaScript #OptionalChaining #NullishCoalescing #DefaultParameters #WebDevelopment #Frontend #DeveloperMaroof #DevTools

🚀 Day 8/21 – JavaScript DOM Project Built a Live Search Filter using JavaScript DOM manipulation. 🛠 Features implemented: ✅ Real-time search filtering ✅ Dynamic DOM updates on user input ✅ Case-insensitive search logic ✅ Improved user experience with instant results 💡 Key Learning: Using the input event and DOM manipulation makes it possible to build real-time interactive search features. #Day8 #JavaScript #DOM #FrontendDevelopment #LearnInPublic

Can you explain the JavaScript event loop? Not because the concept is hard, but because explaining it clearly is what actually matters. Here’s the simplest way to break it down: JavaScript runs in a single thread, using a call stack to execute code. 1. Synchronous code runs first → Functions are pushed to the call stack and executed immediately 2. Async tasks are handled by the browser/environment → e.g. setTimeout, fetch, DOM events 3. Once the call stack is empty → the event loop starts working It processes queues in this order: 👉 Microtasks first (Promises, queueMicrotask) 👉 Then macrotasks (setTimeout, setInterval, I/O) Why? - A and D are synchronous → executed first - Promise (C) → microtask queue → runs next - setTimeout (B) → macrotask → runs last Explaining it step by step is simple — but doing it clearly makes all the difference. #Frontend #JavaScript #WebDevelopment #TechInterviews #SoftwareEngineering

🚨 JavaScript Gotcha: When 0 Actually Matters One of the most subtle bugs in JavaScript comes from using the logical OR (||) for default values. const timeout = userTimeout || 3000; Looks fine… until userTimeout = 0. 👉 JavaScript treats 0 as falsy, so instead of respecting your value, it silently replaces it with 3000. 💥 Result? Unexpected behavior. ✅ The Fix: Use Nullish Coalescing (??) const timeout = userTimeout ?? 3000; This only falls back when the value is null or undefined — not when it’s 0. 💡 When does 0 actually matter? ⏱️ Timeouts & delays → 0 can mean run immediately 📊 Counters & stats → 0 is a valid value, not “missing” 💰 Pricing / discounts → Free (0) ≠ undefined 🎚️ Sliders / configs → Minimum values often start at 0 🧠 Rule of thumb: Use || when you want to catch all falsy values (0, "", false, etc.) Use ?? when you only want to catch missing values (null, undefined) ⚡ Small operator. Big difference. Cleaner logic. #reactjs,#nodejs #JavaScript #WebDevelopment #CleanCode #Frontend #ProgrammingTips #DevTips #CodeQuality #SoftwareEngineering

Day 14/21 : JavaScript DOM (Document Object Model) As part of my 21-Day Full Stack Revision Challenge, today I revised the DOM, which allows JavaScript to interact with and modify web pages. The DOM represents the webpage as a structured tree, making it possible to access and update elements dynamically. > Topics I Covered What is DOM – A representation of the HTML document Selecting Elements – Accessing elements using JavaScript Manipulating Content – Changing text, styles, and attributes Event Handling – Responding to user actions like clicks and inputs > Why It Matters DOM manipulation helps in creating interactive and dynamic web applications instead of static pages. Day 14 completed #FullStackDeveloper #JavaScript #DOM #WebDevelopment #LearningInPublic #21DaysChallenge #CodingJourney