JavaScript Variable Declaration: var, let, or const

JavaScript does NOT use classical inheritance. It uses Prototype inheritance. Example: function Person(name) { this.name = name; } Person.prototype.sayHi = function() { console.log("Hi " + this.name); }; const p1 = new Person("Prakhar"); p1.sayHi(); How it works: JavaScript creates empty object Links it to Person.prototype Assigns this Returns object If property not found on object, JavaScript looks up the prototype chain. This is how inheritance works internally. Understanding prototypes makes debugging easier. #javascript #webdevelopment #frontend #programming

🐞 A tiny JavaScript mistake that can break your code. Look at this snippet: function check(){ let first = 1; let First = 1; let res = 0; if(first == First){ res = 1; return res; } } console.log(res); Looks simple, right? But running this code will throw a ReferenceError. Here’s why 👇 🔹 JavaScript is case-sensitive first and First are two different variables. 🔹 Function scope matters res is declared inside the function, so it cannot be accessed outside of it. That’s why this line fails: console.log(res); ✅ Correct way: const result = check(); console.log(result); 💡 Lesson: Most bugs in programming aren't complex algorithms — they’re small details like scope, naming, and function usage. And those details matter. What’s the smallest bug that cost you the most debugging time? 👨💻 #JavaScript #CodingTips #WebDevelopment #Programming #DeveloperLife

JavaScript behavior that looks completely wrong: console.log([] + []); Output: "" Why? Because + triggers type coercion. Step 1: Both arrays are converted to primitive values. [].toString() → "" Step 2: Now it becomes: "" + "" Which equals: "" Now look at this: console.log([] + {}); Output: "[object Object]" Why? [].toString() → "" {}.toString() → "[object Object]" So it becomes: "" + "[object Object]" Understanding coercion rules prevents unpredictable bugs. JavaScript is simple. Its edge cases are not. #javascript #webdevelopment #programming #frontend #softwareengineering

📊 Day 14 – Poll Answer & Explanation console.log([1,2] + [3,4]); ❓ What will be the output? Many developers expect array concatenation, but JavaScript behaves differently ✅ Step-by-Step Explanation Step 1️⃣ JavaScript sees the `+` operator. The `+` operator can perform: Addition String concatenation Step 2️⃣ When arrays are used with `+`, JavaScript converts them to strings. [1,2].toString() // "1,2" [3,4].toString() // "3,4" Step 3️⃣ Now the operation becomes: "1,2" + "3,4" Step 4️⃣ This performs string concatenation. "1,23,4" ### 🎯 Final Output 1,23,4 📌 Key Concept The `+` operator with arrays converts them into strings first, then performs string concatenation. #JavaScript #WebDevelopment #FrontendDevelopment #Programming #CodingInterview #DeveloperCommunity #100DaysOfCode #LearnToCode

💡 Debounce vs Throttle in JavaScript – A concept every developer should know! Many developers confuse Debounce and Throttle, but understanding the difference can significantly improve application performance. 🔹 Debounce waits until the user stops triggering an event before executing the function. Perfect for: • Search inputs • Autocomplete • API calls 🔹 Throttle ensures a function runs only once within a fixed time interval. Perfect for: • Scroll events • Resize events • Continuous button clicks ⚡ Choosing the right technique helps reduce unnecessary function calls and improves user experience. 📌 Simple rule: Debounce → Wait for inactivity Throttle → Limit execution frequency #JavaScript #WebDevelopment #FrontendDevelopment #CodingTips #Developer #Programming

I practiced destructuring in JavaScript, and it’s a very useful feature. Using destructuring, we can easily extract values from arrays and objects. For arrays, we use square brackets []. For objects, we use curly braces {}. In arrays, values are assigned based on their position, and in objects, they are assigned based on property names. Such a clean and efficient way to work with data. #JavaScript #Destructuring #ES6 #WebDevelopment #LearningJourney

⚠️ The Danger of Splicing Arrays in a Loop "While solving the 'Move Zeroes' challenge today, I encountered a classic JavaScript pitfall: Modifying an array's length while iterating over it. The Mistake: Using .splice() inside a for loop. When you remove an element, the next one shifts left, and your loop index skips it! The Lesson: Always adjust your index or, even better, use the Two-Pointer technique. It's not just safer; it's much more performant for large datasets. Small bugs teach the biggest lessons! 🚀" "Did you know? JavaScript (ES6) allows you to swap array elements in a single line using destructuring : [a, b] = [b, a]. Clean, readable, and efficient!" Feel free to check out my progress and solutions on my LeetCode profile: I've shared my LeetCode profile link in the first comment below! #JavaScript #CodingTips #WebDevelopment #ProblemSolving #LeetCode #AngularDeveloper

I learned about hoisting in JavaScript. Hoisting moves variable and function declarations to the top of their scope before execution. var is hoisted, but only the declaration — not the assigned value. let and const are also hoisted, but they stay in the Temporal Dead Zone until the line where they are declared. Understanding hoisting helps avoid unexpected errors and write more predictable code. #JavaScript #Hoisting #ProgrammingBasics #WebDevelopment #LearningJourney

🚀 Day 11/21 – JavaScript DOM Project Built a Simple Expense Tracker using JavaScript DOM manipulation. 🛠 Features implemented: ✅ Add income and expense transactions ✅ Real-time balance calculation ✅ Transaction history list ✅ Delete transactions ✅ Dynamic UI updates 💡 Key Learning: Learned how to manage application state using arrays and update the DOM dynamically when the data changes. #Day11 #JavaScript #DOM #ExpenseTracker #WebDevelopment #LearnInPublic

⚠️ A Common JavaScript Hoisting Myth Many developers say: “JavaScript moves variable and function declarations to the top of the code.” But that’s not actually true. Nothing is physically moved. What really happens is that before the code starts executing, the JavaScript engine runs a memory creation phase where it scans the code and allocates memory for variables and functions. • "var" - initialized with "undefined" • "let" and "const" - created but stay in the Temporal Dead Zone (TDZ) • Functions - their full definition is stored in memory So hoisting is not about moving code, it’s about how the JavaScript engine prepares memory before execution begins. The deeper I go into JavaScript internals, the more interesting it gets.🤓 #JavaScript #BackendDevelopment #NodeJS #SoftwareEngineering #SystemDesign #Programming #LearningInPublic