Pedro Henrique Alves Cruz’s Post

6 days ago I made a post on: 📌 "Something i figured in JavaScript today that A.I code misinterprets." I am about to share that now, pay close attention. As a developer using JavaScript, this is in connecting with the scopes of JavaScript. The Scope of JavaScript refers to the visibility of variable and functions within a program of codes. Which are: 1. Global scope: this variable is visible anywhere in the javascript program. 2. Function scope: this is a variable created when a function is declared and it's variable and functions are only visible withing that function. A sample of it is: Function funName(){ var fs = "..." alert (fs); console.log(fs); } funName(); Now looking at this, A.I codes misinterprets the function scopes and genrate codes that carries just global scopes or even most times Interchange function scopes with global scopes when giving a variable function. 📌 The risk of this common error in our program will not appear at the beginning of the project but during debugging and code maintenance. Wonder why JavaScript bugs gives you sleepless nights? This is one of the main reasons. This is a call for developers and vibe coders to learn the intimate differences between GLOBAL SCOPE VARIABLES and FUNCION SCOPE VARIABLES. You A.I JavaScript code can cause you harm later if you do not learn this earlier. 📌 A.I. frequently misunderstands Hoisting and the Temporal Dead Zone (TDZ) when creating nested functions. It often defaults to legacy var logic within closure loops (because the bulk of the training data still uses it) rather than modern let/const for block scoping. It optimizes for visual syntax, not runtime safety. Automation without technical intuition creates technical debt. Want more daily strategy from the cutting edge of web infrastructure? connect with snow works #WorksTechnology #JavaScriptMastery #CodingArchitecture #AIPerformance #TechnicalIntuition #WebArchitecture #SoftwareDesign #WebDevStrategy

JavaScript Tricky Question Series Why Promise { <pending> }? Because async functions always return a Promise, no matter what. // What you wrote is equivalent to: function test() { return new Promise((resolve) => { resolve(Promise.resolve(5)); // still a Promise }); } To get the actual value 5, you have 3 options: 1. Using .then() test().then(value => console.log(value)); // 5 2. Using await inside async function async function main() { const value = await test(); console.log(value); // 5 } main(); 3. Using top-level await (ES modules only) const value = await test(); console.log(value); // 5 console.log runs synchronously, but the Promise resolves asynchronously, so by the time it logs, the value isn't ready yet.

Most JavaScript bugs are not because of bad code. They come from wrong assumptions. Example: You think: “This variable should be accessible here” JavaScript says: “Nope. Different scope.” You think: “This will run immediately” JavaScript says: “Wait for the event loop.” You think: “This function forgot the value” JavaScript says: “Closures already stored it.” 👉 JS is predictable. But only if you understand how it thinks. Stop fighting the language. Start understanding it. That’s when everything changes!

Have you ever wanted to create a dynamic object that can intercept operations? The Proxy and Reflect APIs in JavaScript allow you to do just that! How have you utilized these in your projects? ────────────────────────────── Exploring the Proxy and Reflect API in JavaScript Unlock the potential of Proxy and Reflect in your JavaScript code. #javascript #proxy #reflect #apis ────────────────────────────── Key Rules • Use Proxy to create a wrapper around an object to redefine fundamental operations. • Reflect provides methods that mirror the behavior of the Proxy handlers, making your code cleaner. • Always consider performance implications when using proxies, as they can add overhead. 💡 Try This const target = {}; const handler = { get: (obj, prop) => prop in obj ? obj[prop] : 'not found' }; const proxy = new Proxy(target, handler); console.log(proxy.someProperty); ❓ Quick Quiz Q: What does a Proxy do in JavaScript? A: It intercepts and customizes operations on an object. 🔑 Key Takeaway Embrace the power of Proxy and Reflect to create more flexible and maintainable code! ────────────────────────────── Small JavaScript bugs keep escaping to production and breaking critical user flows. Debugging inconsistent runtime behavior steals time from feature delivery.

𝗧𝗵𝗲 𝗝𝗮𝘃𝗮𝗦𝗰𝗿𝗶𝗽𝘁 𝗘𝘃𝗲𝗻𝘁 𝗟𝗼𝗼𝗽 𝗘𝘅𝗽𝗹𝗮𝗶𝗻𝗲𝗱 You want to know how JavaScript handles asynchronous operations. JavaScript runs on a single thread, so it can only execute one task at a time. To manage this, it uses: - Memory Heap to store variables and objects - Call Stack to execute code The Call Stack is where all synchronous code runs. For example, when you call a function, it goes into the stack. JavaScript cannot handle async operations directly. Instead, it uses Web APIs like setTimeout. These run in the background. After async work is completed, callbacks are placed into queues. There are two types of queues: - Microtask Queue (high priority) - Task Queue (low priority) The Event Loop checks the Call Stack and queues. It runs microtasks before tasks. For example, if you use setTimeout and Promise.resolve, the promise will run first. You can handle asynchronous operations without blocking execution. This is done using the Call Stack, Web APIs, queues, and the Event Loop. Source: https://lnkd.in/gBMJuQRE

𝗧𝗵𝗲 𝗝𝗮𝘃𝗮𝗦𝗰𝗿𝗶𝗽𝘁 𝗘𝘃𝗲𝗻𝘁 𝗟𝗼𝗼𝗽 𝗘𝘅𝗽𝗹𝗮𝗶𝗻𝗲𝗱 You want to know how JavaScript handles asynchronous operations. JavaScript runs on a single thread, so it can only execute one task at a time. To manage this, it uses: - Memory Heap to store variables and objects - Call Stack to execute code The Call Stack is where all synchronous code runs. For example, when you call a function, it goes into the stack. JavaScript cannot handle async operations directly. Instead, it uses Web APIs like setTimeout. These run in the background. After async work is completed, callbacks are placed into queues. There are two types of queues: - Microtask Queue (high priority) - Task Queue (low priority) The Event Loop checks the Call Stack and queues. It runs microtasks before tasks. For example, if you use setTimeout and Promise.resolve, the promise will run first. You can handle asynchronous operations without blocking execution. This is done using the Call Stack, Web APIs, queues, and the Event Loop. Source: https://lnkd.in/gBMJuQRE

Most developers don’t struggle with JavaScript — they struggle with debugging it. Here are the core JavaScript errors you must understand if you want to stop wasting hours: • SyntaxError → Your code is invalid. JS won’t even run it. • ReferenceError → You’re using something that doesn’t exist. • TypeError → Wrong operation on the wrong data type. • RangeError → Value is outside allowed limits. • URIError → Broken URI handling. • AggregateError → Multiple errors grouped together. The difference between a beginner and a solid developer? 👉 Not avoiding errors — but quickly understanding and fixing them. If you can read an error and know exactly where and why it happened, you're already ahead of 80% of developers. What’s the most annoying error you’ve faced recently?

🚀 Just finished building my JavaScript Complete Theory Notes / Cheat Sheet 📘⚡ Over the past few days, I compiled a structured roadmap of JavaScript concepts covering everything from fundamentals to advanced topics. Here’s what I included 👇 🔹 Variables & Data Types 🔹 Operators, Type Coercion & Control Flow 🔹 Functions, Scope, Closures & Hoisting 🔹 this keyword and prototypes 🔹 Arrays, Objects, Maps & Sets 🔹 ES6+ features like Destructuring, Spread, Rest, Modules 🔹 Async JavaScript (Callbacks, Promises, Async/Await, Event Loop) 🔹 DOM Manipulation & Event Handling 🔹 Web APIs, Storage, and Modern JS Patterns What started as simple revision notes slowly turned into a complete developer reference guide. The best part? While writing this, I didn’t just memorize syntax, I started understanding how JavaScript actually thinks behind the scenes: ⚡ Call Stack ⚡ Heap Memory ⚡ Event Loop ⚡ Microtasks vs Macrotasks Learning never stops. Next step: applying these concepts in real-world projects and interview-focused problem solving 💻🔥 #JavaScript #WebDevelopment #FrontendDeveloper #ReactJS #FullStackDeveloper #CodingJourney #SoftwareDevelopment #LearningInPublic #TechJourney

Day 14/30 — JavaScript Journey JavaScript Closures 🤯 Hidden Superpower of JS Closures are where JavaScript goes from “basic” to “powerful.” ⚡ A closure happens when a function remembers variables from its outer scope — even after that outer function is done executing. 👉 Simple idea: A function carries its data with it, everywhere it goes 🎒 ⚡ Why Closures Matter • Data Privacy → Hide variables, expose only what’s needed • State Management → Remember values without globals • Core JS Power → Used in callbacks, event handlers, promises, React 🧠 Mental Model Function + its surrounding data = Closure Even if the outer function is gone, the inner one still has access. 🔥 Real Impact Without closures ❌ • Messy global variables • Hard-to-maintain code With closures ✅ • Clean architecture • Controlled data access • Modular, scalable code 🚀 One-Line Insight Closures turn functions into stateful, powerful building blocks 💬 If this clicked, you’re ahead of most developers Comment “CLOSURE” for a real-world example breakdown 👇

𝗧𝗵𝗲 𝗡𝗲𝗪 𝗞𝗲𝗬𝗪𝗼𝗥𝗱 𝗜𝗡 𝗝𝗮𝗩𝗮𝗦𝗰𝗿𝗶𝗽𝗧 You use the new keyword to create instances from classes in JavaScript. But what does new actually do? - It tells JavaScript to treat a function as a constructor and create a new object instance. - It links the new object's prototype to the constructor's prototype. - It binds this to the new object. - It executes the constructor body. - It returns the new object. When you use new with a constructor function, JavaScript performs these steps. - Creates a new empty object. - Links the new object's prototype to the constructor's prototype. - Binds this to the new object. - Executes the constructor body. - Returns the new object. For example: ``` is not allowed, using plain text instead function Person(name, age) { this.name = name; this.age = age; } const ritam = new Person("Ritam", 22); This creates a new instance with its own properties, linked to the shared prototype. You can add methods to the prototype: Person.prototype.sayHello = function() { console.log(`Hi, I'm ${this.name}`); }; Each instance has its own properties, but they share the same prototype methods. Understanding the new keyword is key to how JavaScript's object system works. Source: https://lnkd.in/gsGQpDeR