JavaScript Simplified Series Day 37 Modules

🚀 JavaScript Simplified Series — Day 36 You created a class… Now imagine 👇 You want another class with: 👉 Same properties 👉 Same methods 👉 Plus some extra features Will you rewrite everything again? ❌ That’s inefficient 😵 --- ## 🔥 Solution → Inheritance --- ## 🔹 What is Inheritance? Inheritance allows one class to: 👉 **Reuse properties & methods of another class** --- ## 🔹 Example ```javascript id="inh1" class User { constructor(name) { this.name = name } greet() { console.log("Hello " + this.name) } } class Admin extends User { deleteUser() { console.log("User deleted") } } let admin = new Admin("Abhay") admin.greet() admin.deleteUser() ``` 👉 Output: Hello Abhay User deleted --- ## 🔍 What’s happening? 👉 `Admin` inherited from `User` 👉 So it gets `greet()` automatically 👉 Plus its own method --- ## 🔹 super keyword ```javascript id="inh2" class Admin extends User { constructor(name, role) { super(name) this.role = role } } ``` 👉 `super()` calls parent constructor --- ## 🔥 Real Life Example Think of a **family 👨👩👧** 👉 Parent → basic traits 👉 Child → inherits + adds new traits --- ## 🔥 Simple Summary extends → inheritance super → parent constructor Reuse → no duplication --- ### 💡 Programming Rule **Don’t rewrite code. Reuse it with inheritance.** --- If you want to learn JavaScript in a **simple and practical way**, you can follow these YouTube channels: • Rohit Negi • Hitesh Choudhary (Chai aur Code) --- 📌 Series Progress Day 1 → What is JavaScript Day 2 → Variables & Data Types Day 3 → Type Conversion & Operators Day 4 → Truthy & Falsy + Comparison Operators Day 5 → If Else + Switch + Ternary Day 6 → Loops Day 7 → Break + Continue + Nested Loops Day 8 → Functions Basics Day 9 → Arrow + Default + Rest Parameters Day 10 → Callback & Higher Order Functions Day 11 → Arrays Basics Day 12 → Array Methods Day 13 → Array Iteration Day 14 → Advanced Array Methods Day 15 → Objects Basics Day 16 → Object Methods + this Day 17 → Object Destructuring Day 18 → Spread & Rest Day 19 → Advanced Objects Day 20 → DOM Introduction Day 21 → DOM Selectors Day 22 → DOM Manipulation Day 23 → Events Day 24 → Event Bubbling Day 25 → Event Delegation Day 26 → Async JavaScript Day 27 → Promises Day 28 → Async / Await Day 29 → Fetch API Day 30 → Event Loop Day 31 → Scope Day 32 → Hoisting Day 33 → Closures Day 34 → Prototypes Day 35 → Classes Day 36 → Inheritance Day 37 → Modules (Next Post) --- Follow for more 🚀 #JavaScriptSimplified #javascript #webdevelopment #coding #programming #learninpublic #100DaysOfCode #frontenddevelopment #devcommunity #codingjourney #softwaredeveloper #techcommunity #dailylearning #codeeveryday

🚀 JavaScript Simplified Series — Day 38 You type in a search bar… And API call starts firing on **every single keystroke** 😵 👉 Type “A” → API call 👉 Type “Ab” → API call 👉 Type “Abh” → API call Server overload 💥 App slow 😓 --- ## 🔥 Problem → Too many function calls --- ## 🔥 Solution → Debounce --- ## 🔹 What is Debouncing? Debouncing means: 👉 **Delay execution** 👉 Until user stops typing --- ## 🔹 Example ```javascript id="db1" function debounce(fn, delay) { let timer return function(...args) { clearTimeout(timer) timer = setTimeout(() => { fn(...args) }, delay) } } ``` --- ## 🔹 Usage ```javascript id="db2" function search(query) { console.log("Searching for:", query) } let debouncedSearch = debounce(search, 500) // call this on input event debouncedSearch("Abhay") ``` 👉 Only runs after user stops typing --- ## 🔍 What’s happening? 👉 Every new call clears previous timer 👉 Only last call executes --- ## 🔥 Real Life Example Think of a **remote button 📺** 👉 You press multiple times 👉 TV reacts only after you stop --- ## 🔥 Where is Debounce used? 👉 Search bars 🔍 👉 Resize events 👉 Input fields 👉 API calls --- ## 🔥 Simple Summary Debounce → delay execution Avoid → unnecessary calls Improve → performance --- ### 💡 Programming Rule **Don’t run code on every action. Run it at the right time.** --- If you want to learn JavaScript in a **simple and practical way**, you can follow these YouTube channels: • Rohit Negi • Hitesh Choudhary (Chai aur Code) --- 📌 Series Progress Day 1 → What is JavaScript Day 2 → Variables & Data Types Day 3 → Type Conversion & Operators Day 4 → Truthy & Falsy + Comparison Operators Day 5 → If Else + Switch + Ternary Day 6 → Loops Day 7 → Break + Continue + Nested Loops Day 8 → Functions Basics Day 9 → Arrow + Default + Rest Parameters Day 10 → Callback & Higher Order Functions Day 11 → Arrays Basics Day 12 → Array Methods Day 13 → Array Iteration Day 14 → Advanced Array Methods Day 15 → Objects Basics Day 16 → Object Methods + this Day 17 → Object Destructuring Day 18 → Spread & Rest Day 19 → Advanced Objects Day 20 → DOM Introduction Day 21 → DOM Selectors Day 22 → DOM Manipulation Day 23 → Events Day 24 → Event Bubbling Day 25 → Event Delegation Day 26 → Async JavaScript Day 27 → Promises Day 28 → Async / Await Day 29 → Fetch API Day 30 → Event Loop Day 31 → Scope Day 32 → Hoisting Day 33 → Closures Day 34 → Prototypes Day 35 → Classes Day 36 → Inheritance Day 37 → Modules Day 38 → Debounce Day 39 → Throttle (Next Post) --- Follow for more 🚀 #JavaScriptSimplified #javascript #webdevelopment #coding #programming #learninpublic #100DaysOfCode #frontenddevelopment #devcommunity #codingjourney #softwaredeveloper #techcommunity #dailylearning #codeeveryday

🚀 JavaScript Simplified Series — Day 31 You wrote a variable… But suddenly 😳 👉 It works in one place 👉 But gives error in another Why? 🤔 --- ## 🔥 This is called → Scope --- ## 🔹 What is Scope? Scope defines **where a variable can be accessed** 👉 Kaha use kar sakte ho 👉 Kaha nahi --- ## 🔹 1. Global Scope ```javascript id="sc1" let name = "Abhay" function greet() { console.log(name) } greet() ``` 👉 Accessible everywhere 📌 Global = sab jagah access --- ## 🔹 2. Function Scope ```javascript id="sc2" function test() { let age = 22 console.log(age) } test() console.log(age) ❌ ``` 👉 Error ❌ 📌 Function ke bahar access nahi --- ## 🔹 3. Block Scope (let & const) ```javascript id="sc3" if (true) { let city = "Delhi" console.log(city) } console.log(city) ❌ ``` 👉 Error ❌ 📌 Block ke bahar access nahi --- ## 🔥 var vs let vs const ```javascript id="sc4" if (true) { var x = 10 } console.log(x) // works 😳 ``` 👉 `var` ignores block scope 📌 `let` & `const` follow block scope --- ## 🔥 Real Life Example Think of a house 🏠 👉 Global → pura ghar 👉 Function → ek room 👉 Block → ek drawer Har cheez har jagah access nahi hoti --- ## 🔥 Simple Summary Global → everywhere Function → inside function Block → inside {} --- ### 💡 Programming Rule **Keep variables limited. Smaller scope = fewer bugs.** --- If you want to learn JavaScript in a **simple and practical way**, you can follow these YouTube channels: • Rohit Negi • Hitesh Choudhary (Chai aur Code) --- 📌 Series Progress Day 1 → What is JavaScript Day 2 → Variables & Data Types Day 3 → Type Conversion & Operators Day 4 → Truthy & Falsy + Comparison Operators Day 5 → If Else + Switch + Ternary Day 6 → Loops Day 7 → Break + Continue + Nested Loops Day 8 → Functions Basics Day 9 → Arrow + Default + Rest Parameters Day 10 → Callback & Higher Order Functions Day 11 → Arrays Basics Day 12 → Array Methods Day 13 → Array Iteration Day 14 → Advanced Array Methods Day 15 → Objects Basics Day 16 → Object Methods + this Day 17 → Object Destructuring Day 18 → Spread & Rest Day 19 → Advanced Objects Day 20 → DOM Introduction Day 21 → DOM Selectors Day 22 → DOM Manipulation Day 23 → Events Day 24 → Event Bubbling Day 25 → Event Delegation Day 26 → Async JavaScript Day 27 → Promises Day 28 → Async / Await Day 29 → Fetch API Day 30 → Event Loop Day 31 → Scope Day 32 → Hoisting (Next Post) --- Follow for more 🚀 #JavaScriptSimplified #javascript #webdevelopment #coding #programming #learninpublic #100DaysOfCode #frontenddevelopment #devcommunity #codingjourney #softwaredeveloper #techcommunity #dailylearning #codeeveryday

🚀 JavaScript Simplified Series — Day 32 You used a variable… Before even declaring it 😳 And somehow… it still worked? 🤯 How is that even possible? --- ## 🔥 This is called → Hoisting --- ## 🔹 What is Hoisting? Hoisting means: 👉 JavaScript moves declarations to the **top of their scope** Before execution starts --- ## 🔹 Example (Confusing 😵) ```javascript id="hs1" console.log(x) var x = 10 ``` 👉 Output: undefined 😳 --- ## 🔍 What actually happens? JavaScript internally converts it to: ```javascript id="hs2" var x console.log(x) x = 10 ``` 👉 Declaration upar chali gayi 👉 Value assign baad me hui --- ## 🔹 let & const (Important ⚠️) ```javascript id="hs3" console.log(a) let a = 10 ``` 👉 Error ❌ 📌 Because of **Temporal Dead Zone (TDZ)** --- ## 🔥 What is TDZ? Time between: 👉 Variable declared 👉 Aur initialize hone tak Is duration me access nahi kar sakte --- ## 🔹 Function Hoisting ```javascript id="hs4" greet() function greet() { console.log("Hello") } ``` 👉 Works perfectly ✅ 📌 Functions are fully hoisted --- ## 🔥 Real Life Example Think of a classroom 🏫 👉 Teacher announces names first 👉 Details baad me fill hoti hain 👉 Declaration pehle 👉 Value baad me --- ## 🔥 Simple Summary Hoisting → declarations upar move hoti hain var → undefined milta hai let/const → error (TDZ) function → fully hoisted --- ### 💡 Programming Rule **Always declare variables at the top. Don’t rely on hoisting.** --- If you want to learn JavaScript in a **simple and practical way**, you can follow these YouTube channels: • Rohit Negi • Hitesh Choudhary (Chai aur Code) --- 📌 Series Progress Day 1 → What is JavaScript Day 2 → Variables & Data Types Day 3 → Type Conversion & Operators Day 4 → Truthy & Falsy + Comparison Operators Day 5 → If Else + Switch + Ternary Day 6 → Loops Day 7 → Break + Continue + Nested Loops Day 8 → Functions Basics Day 9 → Arrow + Default + Rest Parameters Day 10 → Callback & Higher Order Functions Day 11 → Arrays Basics Day 12 → Array Methods Day 13 → Array Iteration Day 14 → Advanced Array Methods Day 15 → Objects Basics Day 16 → Object Methods + this Day 17 → Object Destructuring Day 18 → Spread & Rest Day 19 → Advanced Objects Day 20 → DOM Introduction Day 21 → DOM Selectors Day 22 → DOM Manipulation Day 23 → Events Day 24 → Event Bubbling Day 25 → Event Delegation Day 26 → Async JavaScript Day 27 → Promises Day 28 → Async / Await Day 29 → Fetch API Day 30 → Event Loop Day 31 → Scope Day 32 → Hoisting Day 33 → Closures (Next Post) --- Follow for more 🚀 #JavaScriptSimplified #javascript #webdevelopment #coding #programming #learninpublic #100DaysOfCode #frontenddevelopment #devcommunity #codingjourney #softwaredeveloper #techcommunity #dailylearning #codeeveryday Create image based on this

🚀 JavaScript Simplified Series — Day 35 Prototypes are powerful… But let’s be honest 😅 👉 Syntax thoda confusing lagta hai 👉 Hard to read 👉 Not beginner friendly What if we could write the same thing in a **clean and simple way?** 🤔 --- ## 🔥 Solution → Classes --- ## 🔹 What are Classes? Classes are just a **clean syntax over prototypes** 👉 Same power 👉 Better readability --- ## 🔹 Without Class (Old Way) ```javascript id="clx1" function User(name) { this.name = name } User.prototype.greet = function() { console.log("Hello " + this.name) } let u1 = new User("Abhay") u1.greet() ``` --- ## 🔹 With Class (Modern Way 😎) ```javascript id="clx2" class User { constructor(name) { this.name = name } greet() { console.log("Hello " + this.name) } } let u1 = new User("Abhay") u1.greet() ``` 👉 Same result 👉 Cleaner code --- ## 🔹 Adding More Methods ```javascript id="clx3" class User { constructor(name) { this.name = name } greet() { console.log("Hello " + this.name) } sayBye() { console.log("Goodbye") } } ``` --- ## 🔥 Real Life Example Think of a **blueprint 🏗️** 👉 Class = blueprint 👉 Object = actual building Same design → multiple objects --- ## 🔥 Simple Summary Class → cleaner syntax Constructor → initialize values Methods → behavior --- ### 💡 Programming Rule **Write code that humans can read. Classes make code cleaner.** --- If you want to learn JavaScript in a **simple and practical way**, you can follow these YouTube channels: • Rohit Negi --- 📌 Series Progress Day 1 → What is JavaScript Day 2 → Variables & Data Types Day 3 → Type Conversion & Operators Day 4 → Truthy & Falsy + Comparison Operators Day 5 → If Else + Switch + Ternary Day 6 → Loops Day 7 → Break + Continue + Nested Loops Day 8 → Functions Basics Day 9 → Arrow + Default + Rest Parameters Day 10 → Callback & Higher Order Functions Day 11 → Arrays Basics Day 12 → Array Methods Day 13 → Array Iteration Day 14 → Advanced Array Methods Day 15 → Objects Basics Day 16 → Object Methods + this Day 17 → Object Destructuring Day 18 → Spread & Rest Day 19 → Advanced Objects Day 20 → DOM Introduction Day 21 → DOM Selectors Day 22 → DOM Manipulation Day 23 → Events Day 24 → Event Bubbling Day 25 → Event Delegation Day 26 → Async JavaScript Day 27 → Promises Day 28 → Async / Await Day 29 → Fetch API Day 30 → Event Loop Day 31 → Scope Day 32 → Hoisting Day 33 → Closures Day 34 → Prototypes Day 35 → Classes Day 36 → Inheritance (Next Post) --- Follow for more 🚀 #JavaScriptSimplified #javascript #webdevelopment #coding #programming #learninpublic #100DaysOfCode #frontenddevelopment #devcommunity #codingjourney #softwaredeveloper #techcommunity #dailylearning #codeeveryday

🚀 JavaScript Simplified Series — Day 30 JavaScript feels fast… But have you ever wondered 👇 👉 How does it handle multiple tasks at once? 👉 How does async code run without blocking? This is where the **Event Loop** comes in 😎 --- ## 🤯 The Big Confusion JavaScript is **single-threaded** 👉 It can do **one thing at a time** Then how does this work? 👇 ```javascript id="el1" console.log("Start") setTimeout(() => { console.log("Async Task") }, 0) console.log("End") ``` 👉 Output: Start End Async Task Wait… why? 🤔 --- ## 🔥 Behind the Scenes JavaScript has 3 main parts: 👉 Call Stack 👉 Web APIs 👉 Callback Queue --- ## 🔹 Step by Step Flow 1️⃣ `console.log("Start")` → runs first 2️⃣ `setTimeout` → goes to **Web API** 3️⃣ `console.log("End")` → runs next 4️⃣ Callback goes to **Queue** 5️⃣ Event Loop checks → stack empty? 6️⃣ Yes → push callback to stack 👉 Then runs → "Async Task" --- ## 🔍 Visualization ```id="viz1" Call Stack → Executes code Web APIs → Handles async tasks Queue → Stores callbacks Event Loop → Manages everything ``` --- ## 🔥 Real Life Example Think of a **restaurant 🍽️** 👉 Waiter takes order → sends to kitchen 👉 Kitchen prepares food 👉 Meanwhile waiter serves others 👉 When food is ready → serves you 👉 Event Loop = waiter managing tasks --- ## 🔥 Simple Summary JS → single-threaded Async → handled outside Event Loop → manages execution --- ### 💡 Programming Rule **JavaScript is not multi-threaded… but it behaves like it is.** --- If you want to learn JavaScript in a **simple and practical way**, you can follow these YouTube channels: • Rohit Negi • Hitesh Choudhary (Chai aur Code) --- 📌 Series Progress Day 1 → What is JavaScript Day 2 → Variables & Data Types Day 3 → Type Conversion & Operators Day 4 → Truthy & Falsy + Comparison Operators Day 5 → If Else + Switch + Ternary Day 6 → Loops Day 7 → Break + Continue + Nested Loops Day 8 → Functions Basics Day 9 → Arrow + Default + Rest Parameters Day 10 → Callback & Higher Order Functions Day 11 → Arrays Basics Day 12 → Array Methods Day 13 → Array Iteration Day 14 → Advanced Array Methods Day 15 → Objects Basics Day 16 → Object Methods + this Day 17 → Object Destructuring Day 18 → Spread & Rest Day 19 → Advanced Objects Day 20 → DOM Introduction Day 21 → DOM Selectors Day 22 → DOM Manipulation Day 23 → Events Day 24 → Event Bubbling Day 25 → Event Delegation Day 26 → Async JavaScript Day 27 → Promises Day 28 → Async / Await Day 29 → Fetch API Day 30 → Event Loop Day 31 → Scope (Next Post) --- Follow for more 🚀 #JavaScriptSimplified #javascript #webdevelopment #coding #programming #learninpublic #100DaysOfCode #frontenddevelopment #devcommunity #codingjourney #softwaredeveloper #techcommunity #dailylearning #codeeveryday

#SoftwareEngineer_Not_Code_Monkey I was recently revisiting some concepts that used to trip me up in JavaScript: Array Manipulation. Sometimes, the best way to master a concept is to lay them all out, look them in the eye, and have a little "chat" with the code. Yes, I talk to my code—and you should too! Let’s break down the "Internal Dialogue" of a Senior Developer when handling arrays: .map() — The Transformer The Conversation: "Take this array, visit every single element, and give me a new array with the modifications I asked for. Same length, fresh look." Use Case: Formatting currency or wrapping data in UI components. JavaScript const prices = [10, 20, 30]; const formattedPrices = prices.map(price => `$${price}.00`); // Result: ["$10.00", "$20.00", "$30.00"] .filter() — The Gatekeeper The Conversation: "I’ve got a condition. Check every item; if they pass, they join the new array. If they fail? They’re out." Use Case: Removing "Out of Stock" items or finding "Admin" users. .reduce() — The Grinder The Conversation: "Take the whole list, start with this 'bag' (Accumulator) set to 0, and squash everything down into one single value." Use Case: Calculating a shopping cart total or flattening nested data. JavaScript const cart = [100, 200, 300]; const total = cart.reduce((acc, price) => acc + price, 0); // Result: 600 .find() — The Scout The Conversation: "Go find me the first person named 'Ashraf'. Once you find him, stop looking and bring him back to me—not a list, just the man himself." const students = ["Ahmed", "Ashraf", "Sara"]; const winner = students.find(s => s === "Ashraf"); // Result: "Ashraf" .forEach() — The Blue-Collar Worker The Conversation: "Don't give me a new array. Just loop through and do something—log it, send it to an API, or trigger an alert." const tasks = ["Task 1", "Task 2"]; tasks.forEach(task => console.log(`Processing: ${task}`)); .some() & .every() — The Inspectors .some(): "Is there at least one rebel in this list? If yes, give me a true." .every(): "Is everyone following the rules? If even one person fails, give me a false." The Engineer's Takeaway: Immutability Except for forEach and sort, these methods respect the Immutability principle. We don't touch the original array—it’s a "Red Line." We create new versions. This keeps your state predictable and your bugs minimal, especially as your project scales from a simple script to a full-blown freelance system. Stop just "writing code." Start engineering solutions. Which Array method was your "final boss" when you started? #Programming #SoftwareEngineering #JavaScript #CleanCode #WebDevelopment #Frontend #TechCommunity #ReactJS #NodeJS #Freelancing

🚀 JavaScript Simplified Series — Day 34 Objects are powerful… But what if you could **share properties and methods between objects automatically?** 🤔 Without copying code again and again 😵 This is where **Prototypes** come in 🔥 --- ## 🔥 The Problem ```javascript id="pt1" let user1 = { name: "Abhay", greet: function() { console.log("Hello") } } let user2 = { name: "Rahul", greet: function() { console.log("Hello") } } ``` 👉 Same function repeated ❌ 👉 Code duplication ❌ --- ## 🔥 Solution → Prototype JavaScript objects have a hidden property: 👉 **[[Prototype]]** Through this, objects can **inherit properties** --- ## 🔹 Example ```javascript id="pt2" function User(name) { this.name = name } User.prototype.greet = function() { console.log("Hello " + this.name) } let u1 = new User("Abhay") let u2 = new User("Rahul") u1.greet() u2.greet() ``` 👉 Output: Hello Abhay Hello Rahul --- ## 🔍 What’s happening? 👉 `greet()` is not inside object 👉 It is shared via prototype 📌 Memory efficient + reusable --- ## 🔥 Real Life Example Think of a **template 🧾** 👉 Same format 👉 Different data Like: Form template → reused for all users --- ## 🔥 Prototype Chain If property not found: 👉 Object → Prototype → Next Prototype → null --- ## 🔥 Simple Summary Prototype → shared properties Avoid duplication Enable inheritance --- ### 💡 Programming Rule **Don’t repeat logic. Share it using prototypes.** --- If you want to learn JavaScript in a **simple and practical way**, you can follow these YouTube channels: • Rohit Negi • Hitesh Choudhary Choudhary (Chai aur Code) --- 📌 Series Progress Day 1 → What is JavaScript Day 2 → Variables & Data Types Day 3 → Type Conversion & Operators Day 4 → Truthy & Falsy + Comparison Operators Day 5 → If Else + Switch + Ternary Day 6 → Loops Day 7 → Break + Continue + Nested Loops Day 8 → Functions Basics Day 9 → Arrow + Default + Rest Parameters Day 10 → Callback & Higher Order Functions Day 11 → Arrays Basics Day 12 → Array Methods Day 13 → Array Iteration Day 14 → Advanced Array Methods Day 15 → Objects Basics Day 16 → Object Methods + this Day 17 → Object Destructuring Day 18 → Spread & Rest Day 19 → Advanced Objects Day 20 → DOM Introduction Day 21 → DOM Selectors Day 22 → DOM Manipulation Day 23 → Events Day 24 → Event Bubbling Day 25 → Event Delegation Day 26 → Async JavaScript Day 27 → Promises Day 28 → Async / Await Day 29 → Fetch API Day 30 → Event Loop Day 31 → Scope Day 32 → Hoisting Day 33 → Closures Day 34 → Prototypes Day 35 → Classes (Next Post) --- Follow for more 🚀 #JavaScriptSimplified #javascript #webdevelopment #coding #programming #learninpublic #100DaysOfCode #frontenddevelopment #devcommunity #codingjourney #softwaredeveloper #techcommunity #dailylearning #codeeveryday

🚀 JavaScript Simplified Series — Day 33 You wrote a function… It finished execution… But somehow 😳 👉 It still remembers old variables? How is that possible? 🤯 --- ## 🔥 This is called → Closures --- ## 🔹 What is a Closure? A **closure** is when a function 👉 Remembers variables from its outer scope 👉 Even after the outer function has finished --- ## 🔹 Example ```javascript id="cl1" function outer() { let count = 0 return function inner() { count++ console.log(count) } } let counter = outer() counter() counter() counter() ``` 👉 Output: 1 2 3 --- ## 🔍 What’s happening? 👉 `outer()` executed once 👉 `inner()` still remembers `count` 👉 Value persists 😎 --- ## 🔥 Why is this powerful? Because function can **remember state** --- ## 🔹 Real Life Example Think of a **bank account 🏦** ```javascript id="cl2" function bankAccount() { let balance = 1000 return function deposit(amount) { balance += amount console.log(balance) } } let account = bankAccount() account(500) account(200) ``` 👉 Output: 1500 1700 👉 Balance remembered between calls --- ## 🔥 Where are closures used? 👉 Data privacy 👉 Counters 👉 Event handlers 👉 React hooks --- ## 🔥 Simple Summary Closure → function + memory Remembers outer variables Keeps state alive --- ### 💡 Programming Rule **Closures give functions memory. Use them to control data smartly.** --- If you want to learn JavaScript in a **simple and practical way**, you can follow these YouTube channels: • Rohit Negi • Hitesh Choudhary (Chai aur Code) --- 📌 Series Progress Day 1 → What is JavaScript Day 2 → Variables & Data Types Day 3 → Type Conversion & Operators Day 4 → Truthy & Falsy + Comparison Operators Day 5 → If Else + Switch + Ternary Day 6 → Loops Day 7 → Break + Continue + Nested Loops Day 8 → Functions Basics Day 9 → Arrow + Default + Rest Parameters Day 10 → Callback & Higher Order Functions Day 11 → Arrays Basics Day 12 → Array Methods Day 13 → Array Iteration Day 14 → Advanced Array Methods Day 15 → Objects Basics Day 16 → Object Methods + this Day 17 → Object Destructuring Day 18 → Spread & Rest Day 19 → Advanced Objects Day 20 → DOM Introduction Day 21 → DOM Selectors Day 22 → DOM Manipulation Day 23 → Events Day 24 → Event Bubbling Day 25 → Event Delegation Day 26 → Async JavaScript Day 27 → Promises Day 28 → Async / Await Day 29 → Fetch API Day 30 → Event Loop Day 31 → Scope Day 32 → Hoisting Day 33 → Closures Day 34 → Prototype (Next Post) --- Follow for more 🚀 #JavaScriptSimplified #javascript #webdevelopment #coding #programming #learninpublic #100DaysOfCode #frontenddevelopment #devcommunity #codingjourney #softwaredeveloper #techcommunity #dailylearning #codeeveryday

Day 1/100 of Javascript Today Topic : Javascript Engine JS code is first tokenized and parsed into an AST (Abstract Syntax Tree). The interpreter converts this into bytecode and begins execution. While running, the engine identifies hot code and uses a JIT compiler to optimize it into machine code for better performance. 1. What is Tokenizing? Tokenizing = breaking your code into small meaningful pieces (tokens) After tokenizing: Code Part Token Type let keyword x identifier = operator 10 literal ; punctuation 2. What Happens After Tokenizing? Tokens → Parsing Parser converts tokens into: 👉 AST (Abstract Syntax Tree) Example (conceptually): VariableDeclaration ├── Identifier: x └── Literal: 10 3. Why JavaScript is JIT Compiled? JS is called JIT (Just-In-Time) compiled because: 👉 It compiles code during execution, not before. ⚙️ Flow Code → Tokens → AST → Bytecode → Execution → Optimization → Machine Code 🔥 Step-by-Step 1. Interpreter Phase AST → Bytecode Starts execution immediately 👉 Fast start, but not the fastest execution 2. Profiling Engine watches: Which code runs frequently (hot code) 3. JIT Compilation Hot code → compiled into optimized machine code 👉 Now it runs much faster Also looked at different JavaScript engines: 👉V8 (Google) → Uses Ignition (interpreter) + TurboFan (optimizer), heavily optimized for performance 👉SpiderMonkey (Mozilla) → Uses Interpreter + Baseline + IonMonkey (JIT tiers) 👉Chakra (Microsoft) → Has its own JIT pipeline with profiling and optimization stages Each engine has a different internal architecture, but all follow the same core idea. Reference : 1. https://lnkd.in/gvCjZRJK 2. https://lnkd.in/gwcWp-dE 3. https://lnkd.in/gWGiNJZk. 4. https://lnkd.in/g7D4MiQ8 #Day1 #JavaScript #100DaysOfCode