How to Create Regular Expressions in JavaScript

💡 Day 8/50 – Mastering JavaScript’s Subtle Behaviors 🚀 In JavaScript, sometimes the hardest bugs aren’t syntax errors — they’re “Wait… why did that happen?” moments 😅 Today’s Day 8 questions were built around 3 such moments that every developer faces: --- 🧬 1️⃣ Prototype Inheritance — The Hidden Chain When you create an object using Object.create(), it doesn’t copy properties from the parent… it links to it. That means if a property isn’t found in the child, JavaScript looks up the prototype chain to find it. 👉 This “lookup behavior” often confuses devs who expect a fresh, independent copy. So the next time you’re debugging unexpected data access, remember — It might not be your object, it might be its prototype! --- 🧠 2️⃣ The Mystery of Double .bind() You might think rebinding a function twice changes its context again. But nope! Once you bind a function in JavaScript, it’s permanently bound. Calling .bind() again has no effect — the context (the value of this) stays fixed to the first bind. 💡 Why? Because bind() returns a new function with the this value locked in forever. --- 🧩 3️⃣ Type Coercion + Function Conversion Ever tried adding a function to a string like add + "text"? JavaScript doesn’t crash — it converts your function to a string using its internal toString() method! The result isn’t math; it’s a combination of type coercion and string representation. This is one of those delightful quirks that makes JS both fun and… slightly unhinged 😄 --- 📽️ Watch Day 8 Reel: https://lnkd.in/gBHYWgyi Because once you understand the why, no interviewer can trick you again 😉 #JavaScript #FrontendDevelopment #WebDevelopment #JSInterviewQuestions #CodingChallenge #TechLearning #SoftwareEngineering #Techsharingan #Developers

💥Can You Guess the Output(Advanced JavaScript Edition) 🚀 Output Challenge for JavaScript Developers! Let’s test how deep your JS fundamentals really go 👇 What will be the output of this code? (No AI, no console — just brain + logic 🧠) const obj = { name: 'Rohit', greet() { console.log(`Hello, ${this.name}`); }, delayedGreet() { setTimeout(this.greet, 1000); }, }; obj.delayedGreet(); 🧩 Think before you scroll away — Most developers get this wrong in live interviews (even senior ones). 👉 Drop your answer below in the comments Explain why it happens, not just what happens. Let’s see how many get it right 🔥 #JavaScript #Frontend #WebDevelopment #React #Nextjs #CleanCode #DeveloperCommunity #MachineCodingRound #InterviewPreparation

Most beginners write messy if-else logic — pros don’t. In JavaScript, mastering conditional statements means writing logic that’s not just functional, but readable and scalable. This post breaks down every major pattern: 1. if / else / else if 2. switch 3. ternary operator 4. logical & short-circuit operators 5. optional chaining and nullish coalescing real-world validation and role-based logic Want to level up your JavaScript readability game? Share the worst if-else chain you’ve ever written. https://lnkd.in/dVuD2ZWq #JavaScript #WebDevelopment #CodingTips #FrontendDev #ProgrammingBasics #LearnToCode #Nextjs #MERNStack

🚀 Understanding JavaScript: '' vs null vs undefined In my journey as a developer, I’ve found that some of the smallest details make a big difference. One such detail: knowing when to use an empty string (''), null, or undefined. Let’s break it down simply: 🔹 let var1 = '' This is an empty string. You're saying: "I have a string variable, but it currently holds no characters." Type is “string”. 🔹 let var2 = null This is a deliberate assignment of "no value". Use it when you expect a value later, but for now there’s nothing. It signals intention. 🔹 let var3 = undefined This means the variable exists, but is not yet assigned a value (or hasn’t been set explicitly). It’s more a default state than a deliberate one. 🎯 Why this matters Using the wrong one can lead to bugs or confusion for you (and your team) when reading code. Empty strings, null, and undefined each have different behaviours in comparisons, type checks, and program logic. Being intentional improves readability and maintainability of your code. 👉 Takeaway: Use '' when you want a string that doesn’t have content yet. Use null when you know a value will come later, but now there isn’t one. Accept that undefined is often what you get when you forget to assign, rather than something you deliberately choose. 💬 I’d love to hear from you: do you use null deliberately in your code, or mostly rely on undefined? How do you decide between them? Drop your thoughts below. #JavaScript #CodingTips #WebDevelopment #Programming #SoftwareEngineering

Today's Topic: Promise Chaining in JavaScript In JavaScript, Promise chaining allows you to execute asynchronous tasks one after another, ensuring that each step waits for the previous one to finish. Instead of nesting callbacks (callback hell ), promises make your code cleaner and easier to maintain. Example: function step1() { return new Promise((resolve) => { setTimeout(() => { console.log("Step 1 completed ✅"); resolve(10); }, 1000); }); } function step2(value) { return new Promise((resolve) => { setTimeout(() => { console.log("Step 2 completed ✅"); resolve(value * 2); }, 1000); }); } function step3(value) { return new Promise((resolve) => { setTimeout(() => { console.log("Step 3 completed ✅"); resolve(value + 5); }, 1000); }); } // Promise Chaining step1() .then(result => step2(result)) .then(result => step3(result)) .then(finalResult => console.log("Final Result:", finalResult)) .catch(error => console.error("Error:", error)); ✅ Output (after 3 seconds): Step 1 completed ✅ Step 2 completed ✅ Step 3 completed ✅ Final Result: 25 Each .then() runs after the previous promise resolves — making async flow easy to read and manage. --- 🔖 #JavaScript #WebDevelopment #PromiseChain #AsyncProgramming #CodingTips #FrontendDevelopment #Developers #JSConcepts #CodeLearning #100DaysOfCode #WebDevCommunity

💡 **Is JavaScript Multithreaded? Let’s Clear the Confusion!** Many beginners wonder — *is JavaScript single-threaded or multi-threaded?* Here’s the simple answer 👇 🧠 **JavaScript is Single-Threaded.** It has **one call stack**, meaning it can only run **one task at a time**. That’s why we call it a **synchronous, single-threaded language**. But wait... If that’s true, how does JavaScript handle things like: * ⏱️ `setTimeout()` * 🌐 API calls * 🖱️ Event listeners ...without freezing the UI? ✨ The secret lies in the **Browser (or Node.js) environment**. These environments provide **Web APIs** and use **multiple threads** to handle async tasks in the background. Once those tasks are done, the **Event Loop** brings the results back to the main thread — making JavaScript *feel* asynchronous. ✅ **In short:** * JavaScript → Single-threaded 🧵 * Environment (Browser/Node.js) → Handles async tasks in parallel ⚙️ That’s how we can write **non-blocking, asynchronous code** even though JavaScript itself runs on just **one thread**! #JavaScript #Async #Frontend #Backend #NodeJS #EventLoop #WebDevelopment #MERN #React #Coding #Developers

🚀 The `setInterval()` Function (JavaScript) The `setInterval()` function repeatedly executes a function at a specified interval in milliseconds. It's essential to use `clearInterval()` to stop the interval when it's no longer needed to prevent memory leaks and unexpected behavior. `setInterval` can be useful for tasks like updating a clock or polling a server for updates. Careful consideration should be given to the interval duration to avoid performance issues. 💡 Smart people learn from everything. Start now! ✨ Your AI learning companion — 10k concepts, 4k articles, 12k quizzes. Personalized just for you! 📱 Download now: https://lnkd.in/gefySfsc 🔗 Check it out: https://techielearn.in #JavaScript #WebDev #Frontend #JS #professional #career #development

Understanding this in JavaScript this — one of the most misunderstood keywords in JavaScript. It’s simple in theory… until it suddenly isn’t 😅 Here’s what makes it tricky — this depends entirely on how a function is called, not where it’s written. Its value changes with context. Let’s look at a few examples 👇 const user = { name: "Sakura", greet() { console.log(`Hello, I am ${this.name}`); }, }; user.greet(); // "Sakura" ✅ const callGreet = user.greet; callGreet(); // undefined ❌ (context lost) const boundGreet = user.greet.bind(user); boundGreet(); // "Sakura" ✅ (context fixed) Key takeaways 🧠 ✅ this refers to the object that calls the function. ✅ Lose the calling object → lose the context. ✅ Use .bind(), .call(), or .apply() to control it. ✅ Arrow functions don’t have their own this — they inherit from the parent scope. These small details often trip up developers in interviews and real-world debugging sessions. Once you understand the context flow, this becomes a lot less scary to work with. 💪 🎥 I simplified this in my Day 28/50 JS short video— check it out here 👇 👉 https://lnkd.in/gyUnzuZA #javascript #webdevelopment #frontend #backend #programming #learnjavascript #softwaredevelopment #developerslife #techsharingan #50daysofjavascript

🚀 𝗝𝗮𝘃𝗮𝗦𝗰𝗿𝗶𝗽𝘁’𝘀 𝗠𝗼𝘀𝘁 𝗠𝗶𝘀𝘂𝗻𝗱𝗲𝗿𝘀𝘁𝗼𝗼𝗱 𝗞𝗲𝘆𝘄𝗼𝗿𝗱: this If you’ve ever scratched your head wondering why this doesn’t point where you expect — you’re not alone 😅 Let’s break it down 👇 What is this? • In JavaScript, this refers to 𝘁𝗵𝗲 𝗼𝗯𝗷𝗲𝗰𝘁 𝘁𝗵𝗮𝘁’𝘀 𝗲𝘅𝗲𝗰𝘂𝘁𝗶𝗻𝗴 𝘁𝗵𝗲 𝗰𝘂𝗿𝗿𝗲𝗻𝘁 𝗳𝘂𝗻𝗰𝘁𝗶𝗼𝗻 — but its value 𝗱𝗲𝗽𝗲𝗻𝗱𝘀 𝗼𝗻 𝗵𝗼𝘄 the function is called (not where it’s written). • In Regular Function Declarations / Expressions function showThis() {  console.log(this); } showThis(); // In strict mode → undefined | Non-strict → window (in browser) Here, this is determined by the 𝗰𝗮𝗹𝗹𝗲𝗿. When called directly, it defaults to the global object (window), or undefined in strict mode. • In Object Methods const user = {  name: "Alice",  greet() {   console.log(this.name);  } }; user.greet(); // "Alice" ✅ this points to the object 𝗯𝗲𝗳𝗼𝗿𝗲 𝘁𝗵𝗲 𝗱𝗼𝘁 (user in this case). In Arrow Functions const user = {  name: "Alice",  greet: () => console.log(this.name) }; user.greet(); // ❌ undefined Arrow functions 𝗱𝗼𝗻’𝘁 𝗵𝗮𝘃𝗲 𝘁𝗵𝗲𝗶𝗿 𝗼𝘄𝗻 this — they 𝗶𝗻𝗵𝗲𝗿𝗶𝘁 it from the surrounding (lexical) scope. So here, this refers to the global object, not user. 💡 𝗤𝘂𝗶𝗰𝗸 𝗧𝗶𝗽: Use regular functions for object methods if you need access to the object’s properties. Use arrow functions when you want to preserve the parent scope’s this (like inside a class or callback). 👉 Mastering this is one of the biggest “Aha!” moments in JavaScript. What’s your favorite trick or gotcha with this? #JavaScript #WebDevelopment #Frontend #Coding #LearnToCode #JS #this #software