Pure Functions, Higher-Order Functions & Currying in JavaScript

Assalam o Alaikum everyone, JavaScript Lesson 29 is here: Reference vs Value, Shallow Copy, Deep Copy & Immutable Patterns. This lesson covers one of the most important JavaScript concepts for writing clean and predictable code: understanding how values are stored, copied, and updated in memory. I explained the difference between primitive values and reference values, then demonstrated what happens when you assign objects and arrays directly. From there, I showed how to create shallow copies using spread syntax and Object.assign(), and why shallow copy can still cause problems with nested objects. I also covered deep copy using both: - JSON.parse(JSON.stringify()) - structuredClone() After that, I moved into immutable programming patterns, where I showed how to update arrays and objects without mutating the original data using: - filter() - map() - spread syntax - destructuring This is a very practical topic for JavaScript developers because immutability helps prevent bugs and makes code easier to maintain in real projects. Watch the lesson: https://lnkd.in/dSeTxYPP #JavaScript #ReferenceVsValue #ShallowCopy #DeepCopy #ImmutablePatterns #JavaScriptTutorial #WebDevelopment #FrontendDevelopment #Programming #CodingTutorial #DeveloperMaroof #LearnJavaScript #JavaScriptBasics #ModernJavaScript #SpreadOperator #ObjectAssign #StructuredClone #Immutability #JSConcepts #JavaScriptLessons

One small word in JavaScript causes a lot of confusion: undefined. Many developers encounter it but don’t fully understand why it appears. In my latest article, I break it down in a practical way: • What undefined actually means • Common scenarios where it shows up • Mistakes developers often make • How to avoid it in real projects This is especially useful if you're learning JavaScript or improving your debugging skills. 🔗 Read the full article: https://lnkd.in/gaGDuAHp Curious — what was the most confusing JavaScript concept for you when you started? #JavaScript #WebDevelopment #FrontendDevelopment #Programming #Coding #SoftwareDevelopment #Debugging #LearnJavaScript

𝐃𝐚𝐲 𝟗/𝟏𝟓 𝐨𝐟 𝐦𝐲 𝐉𝐚𝐯𝐚𝐒𝐜𝐫𝐢𝐩𝐭 𝐉𝐨𝐮𝐫𝐧𝐞𝐲 🚀 Day 9… and today felt different. For the first time, I saw JavaScript actually changing something on the screen. That moment felt amazing. 💡 What I learned: DOM (Document Object Model) How JavaScript interacts with HTML getElementById() and querySelector() 🧠 What I understood: JavaScript is not just logic… It can control what users see on a webpage. For example: Click a button → text changes That’s JavaScript in action. At first, I was confused about how JS connects with HTML… But when I tried it myself, it finally clicked. 📌 My biggest takeaway: Seeing your code work on screen hits different. This is where things start to feel real. Still learning… Still exploring… See you on Day 10 🚀 #JavaScript #CodingJourney #LearningInPublic #Day9 #DOM #WebDevelopment #Consistency #Programming

Day 6 / 30 - JavaScript Coding Practice Today’s problem: Roman to Integer var romanToInt = function (s) { if (s.length > 15) { return; } const romanMap = new Map([ ['I', 1], ['V', 5], ['X', 10], ['L', 50], ['C', 100], ['D', 500], ['M', 1000] ]); let sum = 0; let preValue = 0; for (let k = s.length - 1; k >= 0; k--) { let currentVal = romanMap.get(s[k]); if (currentVal < preValue) { sum -= currentVal; } else { sum += currentVal; } preValue = currentVal; } return sum; }; 💡 Key Insight: Instead of scanning from left to right, I iterated from right to left to easily handle subtraction cases like IV (4) and IX (9). 👉 If a smaller value comes before a larger one → subtract 👉 Otherwise → add #JavaScript #DSA #CodingPractice #ProblemSolving #100DaysOfCode #FrontendDevelopment

🚀 Mastering JavaScript Functions: The Ultimate Guide! 🚀 Functions in JavaScript are reusable blocks of code that perform specific tasks when called. They help organize code and make it more efficient by reducing repetition. For developers, understanding functions is essential for writing clean, modular code and improving code readability. Here's a step-by-step breakdown to create and call functions in JavaScript: 1️⃣ Declare the function using the `function` keyword. 2️⃣ Add parameters inside the parentheses to pass data to the function. 3️⃣ Write the code block within curly braces to define the function's logic. 4️⃣ Call the function by using its name followed by parentheses, passing arguments if needed. 🚨 Pro Tip: Always give meaningful names to functions for better code understanding and maintenance. 💡 Common Mistake Alert: Forgetting to return a value from a function when necessary can lead to unexpected results. 🤔 Question: What's your favorite use case for JavaScript functions? Share below! 🌐 View my full portfolio and more dev resources at tharindunipun.lk #JavaScript #Functions #CodingTips #WebDevelopment #Programming #CodeNewbie #DeveloperCommunity #LearnToCode #TechTalks

I recently started diving deeper into JavaScript, and honestly… one concept completely changed how I see code execution 🤯 At first, I used to just write code and expect it to “run.” But then I discovered what actually happens behind the scenes 👇 JavaScript doesn’t just execute code directly. It goes through a process: 🔹 First, it creates a Global Execution Context 🔹 Then comes the Memory Phase (where variables get stored as undefined and functions are fully saved) 🔹 After that, the Execution Phase runs code line by line 🔹 And everything is managed using a Call Stack (LIFO — Last In, First Out) Understanding this made things like hoisting, function calls, and even bugs feel way less random. Now when I write code, I don’t just see syntax — I can actually visualize what the JavaScript engine is doing step by step 🧠⚡ Still learning, but this was one of those “aha” moments that made everything clearer. If you're learning JavaScript, don’t skip this part — it’s a game changer 🚀 #JavaScript #WebDevelopment #LearningJourney #Frontend #Programming #Developers

Scope vs Closure in JavaScript — Explained Simply Understanding the difference between Scope and Closure is crucial for writing clean and efficient JavaScript code. While Scope defines where variables are accessible, Closure allows functions to remember their lexical environment even after execution. This concept is widely used in: • Data encapsulation • Function factories • Callbacks & async programming If you’ve ever been confused between these two, this guide will help you clear it with practical examples. 👉 Read the full article: https://lnkd.in/ga8WaNiA #JavaScript #FrontendDevelopment #WebDevelopment #Programming #Coding #SoftwareDevelopment #LearnJavaScript #InterviewPrep

Some JavaScript concepts sound simple but create confusion in real projects. One common example is Debounce vs Throttle. Both are used to control how frequently a function executes when events happen repeatedly, such as scrolling, resizing, or typing in an input field. Understanding the difference helps developers build better-performing and more responsive applications. In this article, I explained the concept with simple examples so developers can easily understand when to use Debounce and when to use Throttle. Read the article: Debounce vs Throttle in JavaScript https://lnkd.in/gK5NE4Cn #JavaScript #FrontendDevelopment #WebDevelopment #SoftwareDevelopment #Programming #Coding

Understanding the Event Loop in JavaScript is a turning point for every developer. Many developers use async features like promises, setTimeout, or async/await daily — but very few truly understand what happens behind the scenes. I’ve written a detailed yet easy-to-understand article that breaks down: ✔ Call Stack ✔ Callback Queue ✔ Microtask Queue ✔ Execution Order If you want to strengthen your JavaScript fundamentals and avoid common async mistakes, this will definitely help. 👉 Read the full article: https://lnkd.in/gDhwvmUc I’d love to hear your thoughts — what was the hardest concept for you when learning the Event Loop? #JavaScript #SoftwareDevelopment #WebDevelopment #FrontendDevelopment #AsyncProgramming #Coding #TechLearning

🚀 Day 4 of my JavaScript Coding Practice Today’s problem: Two Sum var twoSum = function(nums, target) { const map = new Map(); // Store: { value : index } for (let i = 0; i < nums.length; i++) { const complement = target - nums[i]; // If the needed number is already in our map, we found the pair! if (map.has(complement)) { return [map.get(complement), i]; } // Otherwise, save the current number and its index map.set(nums[i], i); } return []; // Return empty if no pair is found }; 💡 Instead of using brute force (O(n²)), I used a HashMap approach to solve it in O(n) time. Key takeaway: Understanding how to trade space for time can significantly optimize performance. Small steps every day → Big improvements over time 📈 #JavaScript #DSA #CodingPractice #100DaysOfCode #FrontendDevelopment