How to Optimize React Components with memo and useMemo

Ever wondered how JavaScript really works behind the scenes? It’s not magic, it’s a clever system working together. The JS engine runs your code using a call stack and heap, while the browser adds extra powers like Web APIs (for setTimeout, fetch, and DOM events). Then comes the Event Loop, making sure JavaScript stays fast, non-blocking, and asynchronous even though it runs on a single thread. Once you get this, async code suddenly clicks. #JavaScript #WebDevelopment #Frontend #AsyncProgramming #EventLoop #Learning

#TIL The “You Don’t Need” series is a great reality check for many long-lived JS habits. One of the classics: You don’t need Lodash anymore. Most of its utilities are now built into the language — Array.flatMap, Object.entries, String.replaceAll, and so on. And for teams who still want familiar APIs, there’s a modern alternative: ES Toolkit — smaller, faster, actively maintained, fully typed, and even Lodash-compatible. Resources worth checking: • https://lnkd.in/e_VkCk_Y • https://lnkd.in/e7wCZBQx • https://es-toolkit.dev/ Lodash/Underscore has served us well — but modern JS gives us cleaner, faster, and native ways to get the same job done. #JavaScript #Frontend #WebDevelopment #Performance #Tooling #YouDontNeedSeries

🧠Did you know ? Even an empty JavaScript file isn't actually empty. When JS runs, the engine automatically creates: 1) Global Execution Context 2) Global Object (window) 3) this -> points to window in browsers ( In Browsers this === window ) Before a single line of your code executes, memory is allocated and the first execution context is already sitting in the call stack. That is the hidden setup behind every JavaScript program. #Javascript #Webdevelopment #Frontend

Day 3: JSX 🧠 JSX looks like HTML — but it’s not! JSX is JavaScript syntax that returns UI. You can embed variables, conditions, loops — right inside your “HTML.” Example: const name = "React"; return <h1>Hello {name}!</h1>; 💡 Rule: Always return one parent element. JSX = Power + Simplicity. Once you get it, React feels like magic. Comment 👍🏻 if you understood JSX! #JSX #ReactJS #FrontendDevelopment #ReactForBeginners #WebDevelopment

The Simple JS Experiment That Completely Changed How I See Constructors Most JavaScript developers learn constructors one way: create, initialize, return the instance. That’s the story. That’s what everyone teaches. But then recently I realized that story is missing something. Today I’m going to show you why constructors returning functions exist, what they actually enable, and why this weird pattern solves problems that rigid constructors just can’t touch. #javascript #typescript #web https://lnkd.in/d5n3x8TV Let’s get started with the interesting part.

Today I learned about three important JavaScript loops: forEach() for...in for...of Each one has its own purpose: forEach() — used to loop through array elements for...in — used to iterate over object keys for...of — used to loop through iterable values like arrays or strings Understanding the difference between them really cleared things up for me 💡 #JavaScript #WebDevelopment #LearningJourney #Frontend #100daysofcode

🚀 JavaScript Hoisting Explained (Simply!) Hoisting means JavaScript moves all variable and function declarations to the top of their scope before code execution. If that definition sounds confusing, see this example 👇 console.log(a); var a = 5; Internally, JavaScript actually does this 👇 var a; // declaration is hoisted (moved up) console.log(a); a = 5; // initialization stays in place ✅ Output: undefined --- 🧠 In Short: > Hoisting = JS reads your code twice: 1️⃣ First, to register variables & functions 2️⃣ Then, to execute the code line by line --- 💡 Tip: var → hoisted & initialized as undefined let / const → hoisted but not initialized (stay in Temporal Dead Zone) --- #JavaScript #Hoisting #WebDevelopment #CodingTips #JSInterview #Frontend #React #100DaysOfCode

Understanding Hoisting in JavaScript Have you ever wondered how JavaScript can use variables or functions even before they’re declared in the code? 🤔 That’s because of a concept called Hoisting. Hoisting means JavaScript moves variable and function declarations to the top of their scope before code execution. Example 👇 console.log(x); // undefined var x = 10; Here, the variable x is hoisted, but only its declaration, not its value. That’s why you get undefined — not an error. However, let and const behave differently. They are also hoisted but remain uninitialized until their declaration is reached — this period is called the Temporal Dead Zone (TDZ). 📘 Quick Tip: Always declare your variables at the top of their scope to keep your code predictable and clean. #JavaScript #FrontendDevelopment #WebDevelopment #FrontendCountdown #ReactJS #NextJS #TypeScript

Ever seen a variable live even after its function is done? 🤔 That’s not a bug — that’s Closure, one of JavaScript’s most powerful (and tricky) features 💡 Let’s look at a simple example 👇 function counter() { let count = 0; return function () { count++; console.log(count); }; } const increment = counter(); increment(); // 1 increment(); // 2 increment(); // 3 Wait… how does count still remember its value? Didn’t the counter() function finish already? 😅 Here’s the magic 🪄 > A closure allows a function to “remember” the variables from the scope in which it was created — even after that scope is gone. In this example, The inner function still has access to count, Because it closes over the variables from its outer function. That’s why we call it a Closure 🔁 Closures are the reason we can create: ✅ Private variables ✅ Function factories ✅ Modular, memory-efficient code In short — > A closure is how JavaScript gives functions memory 🧠 #JavaScript #Closures #WebDevelopment #Frontend #MERNStack #NodeJS #ReactJS #Coding #SoftwareEngineering #Developers #JSFundamentals

Top-level await in JavaScript. In short: Top-level await turns modules into truly asynchronous building blocks — letting JavaScript handle async dependencies naturally, such as an HTTP request for data from the backend. #JavaScript #WebDevelopment #Frontend