WebAssembly Performance Gains Compared to JavaScript

Day 179: Peeling Back the JavaScript Layers 🧅 Today was all about moving beyond "how to code" and diving into how JavaScript actually works under the hood. I spent the day dissecting objects, the prototype chain, and the evolution of asynchronous patterns. 🧬 The Prototype Power I finally stopped looking at __proto__ as a mystery and started seeing it as a roadmap. Understanding how objects inherit properties from their parents—and how we can extend built-in objects with custom methods like getTrueLength()—is a total game-changer for writing dry, efficient code. ⏳ The Async Evolution: Escaping "Hell" We’ve all seen it: the pyramid of doom known as Callback Hell. Today, I practiced refactoring those nested messes into clean Promises and eventually into the sleek, readable Async/Await syntax. It's not just about making the code work; it's about making it readable for the "future me." 👯 Shallow vs. Deep Copy One of the most important lessons today was realizing that the Spread Operator (...) isn't a magic wand for copying. Shallow Copy: Quick and easy, but nested objects are still linked to the original. Deep Copy: Using JSON.parse(JSON.stringify()) to completely sever ties and create a truly independent clone. Key takeaways: Object Mastery: Using Object.values() and hasOwnProperty to navigate data safely. Array Essentials: Re-mastering map, reduce, and Array.from(). The 'New' Keyword: Understanding how it establishes that hidden link to the constructor's prototype. If you’re not understanding the prototype chain, you’re only using 50% of JavaScript’s power! #100DaysOfCode #JavaScript #WebDevelopment #CodingJourney #SoftwareEngineering #AsyncJS #Prototypes #BuildInPublic

🧠 The Call Stack in JavaScript — Simplified JavaScript executes code using something called the call stack. It follows one simple rule: Last In, First Out (LIFO). Every time a function runs, it gets pushed onto the stack, and when it finishes, it gets popped off. Understanding this small concept makes debugging errors like “Maximum call stack size exceeded” much easier. It also helps you truly understand recursion and how JavaScript executes code step by step. Read more here 👉 https://lnkd.in/g2CCpCqs #JavaScript #WebDevelopment #Programming

🚀 JavaScript Hoisting Explained Clearly Most developers hear about hoisting… But very few truly understand what actually happens behind the scenes. Let’s break it down. When JavaScript runs your code, it does NOT execute it line by line immediately. First, it creates something called the Execution Context. There are two main phases: 1️⃣ Creation Phase (Hoisting Phase) 2️⃣ Execution Phase 🔵 Creation Phase (Hoisting Phase) During this phase: • Memory is allocated for variables and functions • Function declarations are stored completely in memory • var variables are initialized with undefined • let and const are hoisted but remain in the Temporal Dead Zone (TDZ) Example that works: greet(); function greet() { console.log("Hello"); } Example that throws an error: sayHi(); const sayHi = function () { console.log("Hi"); }; Reason: Only the variable is hoisted, not the function expression. 🔴 Execution Phase Now JavaScript executes the code line by line. • Variables receive their actual values • Functions run when called Important Insight Hoisting does NOT mean JavaScript moves your code to the top. It means JavaScript allocates memory before execution begins. If you understand hoisting deeply, you automatically understand: • Execution Stack • Scope Chain • Closures • TDZ • var vs let vs const Master this concept once, and JavaScript starts making real sense. #JavaScript #WebDevelopment #Frontend #ExecutionContext #Hoisting #LearnToCode #Programming #Developers

𝗪𝗵𝘆 𝗱𝗼𝗲𝘀 𝗝𝗮𝘃𝗮𝗦𝗰𝗿𝗶𝗽𝘁 𝗹𝗲𝘁 𝘆𝗼𝘂 𝘂𝘀𝗲 𝘃𝗮𝗿𝗶𝗮𝗯𝗹𝗲𝘀 𝗯𝗲𝗳𝗼𝗿𝗲 𝘁𝗵𝗲𝘆’𝗿𝗲 𝗱𝗲𝗰𝗹𝗮𝗿𝗲𝗱? 🤔 Hi everyone! Following up on my last post, Part 2 of my JavaScript deep-dive series is now live on Medium! Today, we’re tackling one of the most famous (and often misunderstood) behaviors in the language: 𝗛𝗼𝗶𝘀𝘁𝗶𝗻𝗴. If you’ve ever wondered why var gives you undefined, but let throws a ReferenceError, or why function declarations work anywhere in your file, this article is for you. 𝗜𝗻 𝗣𝗮𝗿𝘁 2, 𝗜 𝗯𝗿𝗲𝗮𝗸 𝗱𝗼𝘄𝗻:  • 𝗧𝗵𝗲 𝗣𝗿𝗲𝗽𝗿𝗼𝗰𝗲𝘀𝘀𝗶𝗻𝗴 𝗦𝘁𝗲𝗽: Why the engine scans your code before running it.  • 𝗧𝗵𝗲 "𝘃𝗮𝗿" 𝗠𝘆𝘀𝘁𝗲𝗿𝘆: Why declarations are hoisted, but values are not.  • 𝗙𝘂𝗻𝗰𝘁𝗶𝗼𝗻 𝘃𝘀. 𝗖𝗹𝗮𝘀𝘀 𝗛𝗼𝗶𝘀𝘁𝗶𝗻𝗴: Why they behave so differently.  • 𝗧𝗵𝗲 𝗧𝗲𝗺𝗽𝗼𝗿𝗮𝗹 𝗗𝗲𝗮𝗱 𝗭𝗼𝗻𝗲 (𝗧𝗗𝗭): Demystifying the "forbidden zone" of modern JS. I also address the biggest myth in JS: 𝗗𝗼𝗲𝘀 𝘁𝗵𝗲 𝗲𝗻𝗴𝗶𝗻𝗲 𝗮𝗰𝘁𝘂𝗮𝗹𝗹𝘆 "𝗺𝗼𝘃𝗲" 𝘆𝗼𝘂𝗿 𝗰𝗼𝗱𝗲 𝘁𝗼 𝘁𝗵𝗲 𝘁𝗼𝗽 𝗼𝗳 𝘁𝗵𝗲 𝗳𝗶𝗹𝗲? Check out the full breakdown here: https://lnkd.in/dGZJMbB4 🔗 I’d love to hear your thoughts or any "Hoisting horror stories" you've encountered in your own projects! 𝗡𝗲𝘅𝘁 𝘂𝗽: We move from how variables are registered to where they live: 𝗦𝗰𝗼𝗽𝗲 𝗮𝗻𝗱 𝘁𝗵𝗲 𝗦𝗰𝗼𝗽𝗲 𝗖𝗵𝗮𝗶𝗻. #JavaScript #WebDevelopment #Hoisting #SoftwareEngineering #TechCommunity #CodingLife #Medium

🚀 Just published: The JavaScript Variable Declaration Trilogy After years of writing JavaScript, I decided to go beyond the usual "use const by default" advice and explore the why behind var, let, and const. In this deep dive, I cover: ✅ The Temporal Dead Zone (and why it catches bugs you didn't know you had) ✅ The closure gotcha that's bitten every JS developer at least once ✅ Why const doesn't mean immutable (and what it actually protects) ✅ Performance implications nobody talks about ✅ Real-world horror stories and how let/const solve them This isn't another surface-level comparison it's about building the right mental models to write bulletproof JavaScript. Full breakdown with visual walkthroughs 👇 https://lnkd.in/ehQs6Nbf #JavaScript #WebDevelopment #Programming #ES6 #SoftwareEngineering #CodingTips #FrontendDevelopment

JavaScript looks simple on the surface, but the real story starts after your code runs. Call stack, memory allocation, garbage collection and event loop. these aren’t “advanced concepts” they’re the basics of performance, debugging and async. I wrote an in-depth article about how JavaScript really executes code, without code examples. just conceptual frameworks that will shift your thinking. If you’ve ever asked yourself: - Why async code is “weird”. - Why memory is always growing. - Why JavaScript is fast despite being Single Threaded. This will answer those questions. 🔗 https://lnkd.in/dkNMzDv8 #JavaScript #JavaScriptInternals #AsyncJavaScript #EventLoop #WebDevelopment #SoftwareEngineering #Developers

Claims about WebAssembly’s speed are everywhere, but the real question is how it compares under load. Jessica Wachtel walks through a hands-on performance test against JavaScript using a Rust-based image processor.

The tale of two dots: Mastering the difference between Spread vs. Rest in JavaScript. 🧐 If you are learning modern JavaScript, the three dots syntax (...) can be incredibly confusing. Depending on where you place them, they either act as the Spread operator or the Rest operator. They look identical, but they do complete opposite jobs. Here is the simplest way to differentiate them. ✅ 1. The Spread Operator (The "Unpacker") Think of Spread as opening a suitcase and dumping everything out onto the bed. It takes an iterable (like an array or an object) and expands it into individual elements. Common Use Cases: Copying arrays/objects (shallow copies). Merging arrays/objects together. Passing elements of an array as separate arguments into a function. ✅ 2. The Rest Operator (The "Gatherer") Think of Rest as taking leftovers on a table and putting them all into one Tupperware container. It does the opposite of spread. It collects multiple separate elements and condenses them into a single array or object. Common Use Cases: Handling variable numbers of function arguments. Destructuring arrays or objects to grab "the rest" of the items. 💡 The Golden Rule to Tell Them Apart It’s all about context. Look at where the dots are used: If it’s used in a function call or on the right side of an equals sign, it’s usually Spread (it's expanding data). If it’s used in a function definition or on the left side of an equals sign (destructuring), it’s usually Rest (it's gathering data). Which one do you find yourself using more often in your daily work? #JavaScript #WebDevelopment #CodingTips #SoftwareEngineering #Frontend

Post Title: Demystifying JavaScript Hoisting & Execution Context 🧠💻 Ever wondered why you can access a variable in JavaScript before you’ve even declared it? Or why let and const sometimes throw a "Temporal Dead Zone" error while var just gives you undefined? I recently broke down these concepts on the whiteboard, and they are the "make or break" fundamentals for every JS developer. Here’s the recap: 1. Hoisting: The "Mental Move" JavaScript moves declarations to the top of their scope during the compilation phase. But not all declarations are treated equally: var: Hoisted and initialized as undefined. let & const: Hoisted but not initialized. They live in the Temporal Dead Zone (TDZ) until the code reaches their declaration. Function Declarations: Fully hoisted! You can call the function even before it's written in the script. Arrow Functions/Expressions: Treated like variables (meaning no hoisting if you use let or const). 2. Behind the Scenes: The Global Execution Context (GEC) The whiteboard illustrates how the JS Engine handles your code in two distinct phases: Memory Creation Phase: The engine scans the code and allocates memory for variables and functions. (e.g., a becomes undefined, c() gets its entire code block). Code Execution Phase: The engine executes the code line-by-line, assigning values (e.g., a = 10) and executing function calls. 3. The Call Stack Every time a function like c() is called, a new Execution Context is pushed onto the Call Stack. Once the function finishes, it’s popped off. Understanding this stack is the key to mastering recursion and debugging "Stack Overflow" errors! 💡 Pro-Tip: Always use let and const to avoid the "undefined" bugs that come with var hoisting. Clean code is predictable code! What’s one JS concept that took you a while to "click"? Let’s discuss in the comments! 👇 #JavaScript #WebDevelopment #ProgrammingTips #CodingLife #SoftwareEngineering #Frontend