ROHAN T.’s Post

🚨 JavaScript Interview Question What will be the output? 🤔 function greet(name) { if (name === undefined) { console.log("Hello, guest!"); } else { console.log("Hello, " + name); } } greet(); greet("Amrutha"); greet("Vineeth", "How are you?"); Looks simple… but there’s a twist 👀 👉 What will be the output? 👉 Why does the last call behave differently? Bonus: How does JavaScript handle extra arguments? 🔥 #JavaScript #FrontendInterview #WebDevelopment #CodingInterview #ProductBasedCompany

🚀🔥 Mastering JavaScript String Methods & Real-Time Problems 🔥🚀 🚀Today I focused on strengthening my String fundamentals + problem-solving skills 💻🧠 ✨ What I Practiced: 🔹 Clean user input by removing unwanted spaces 🔹 Case-insensitive comparisons (real login scenarios) 🔹 Searching words inside strings 🔹 Extracting specific parts of strings (like usernames, substrings) 🔹 Converting data types (string ↔ number) 🔹 Working with arrays from strings 💡 Real-Time Use Cases I Solved: ✅ Email username extraction ✅ File type validation (.html check) ✅ Password masking using symbols ✅ Replacing spaces for URL-friendly strings ✅ Checking word existence in sentences 🧠 Logic-Based Problems Covered: 🔸 Reverse a string (without built-in methods) 🔸 Check palindrome 🔸 Count vowels in a string 🔸 Find frequency of characters 🔸 First repeating & non-repeating character 🔸 Remove duplicate characters 🔸 Check anagrams 🔸 String compression (aaabbc → a3b2c1) 🔸 Reverse case transformation (hELLO wORLD) 🔥 Key Learnings: ✔️ Strings are immutable (operations return new values) ✔️ Combining multiple methods is powerful ✔️ Logic building is more important than memorizing methods ✔️ Writing generic solutions is crucial for interviews #JavaScript #WebDevelopment #FrontendDeveloper #CodingJourney #ProblemSolving #DSA #LearningInPublic #CareerGrowth #TechJourney

📘 𝐉𝐚𝐯𝐚𝐒𝐜𝐫𝐢𝐩𝐭 𝐈𝐧𝐭𝐞𝐫𝐯𝐢𝐞𝐰 𝐌𝐨𝐝𝐮𝐥𝐞 (𝐁𝐚𝐬𝐢𝐜) -> Save this checklist, I hope it will be of great use in your next interview revision! 👇 𝐒𝐞𝐜𝐭𝐢𝐨𝐧 2: 𝐕𝐚𝐫𝐢𝐚𝐛𝐥𝐞𝐬 11. 𝐖𝐡𝐚𝐭 𝐢𝐬 𝐮𝐧𝐝𝐞𝐟𝐢𝐧𝐞𝐝? -> JavaScript's default value is when nothing is assigned. This is a default behavior of JavaScript. If you have declared a variable (var age;) but have not given a value, JavaScript will automatically call it undefined. 12. 𝐖𝐡𝐚𝐭 𝐢𝐬 𝐍𝐚𝐍? -> Not a Number — invalid number result. This comes when you do something wrong while doing math. Example: If you multiply your name by 10 ("Sohan" * 10), JavaScript will say—brother, this is not a number, so the output will be NaN. 13. 𝐖𝐡𝐚𝐭 𝐢𝐬 𝐧𝐮𝐥𝐥? -> Intentionally assigning an empty value. You do this intentionally. When you want a variable to be empty now, and later the data will come, then you set age = null; yourself. 14. 𝐖𝐡𝐚𝐭 𝐢𝐬 𝐜𝐨𝐧𝐜𝐚𝐭𝐞𝐧𝐚𝐭𝐢𝐨𝐧? -> Adding two strings or concatenating two texts. For example: "Hello " + "World". 15. 𝐖𝐡𝐚𝐭 𝐢𝐬 𝐈𝐧𝐟𝐢𝐧𝐢𝐭𝐲? -> When a number is divided by 0. 50/0 result infinity. 16.𝐇𝐨𝐰 𝐭𝐨 𝐚𝐬𝐬𝐢𝐠𝐧 𝐝𝐚𝐭𝐚 𝐭𝐨 𝐚 𝐯𝐚𝐫𝐢𝐚𝐛𝐥𝐞? / 𝐇𝐨𝐰 𝐭𝐨 𝐚𝐬𝐬𝐢𝐠𝐧 𝐚 𝐯𝐚𝐫𝐢𝐚𝐛𝐥𝐞 𝐝𝐚𝐭𝐚? -> let x; x = 10; 17. 𝐕𝐚𝐫𝐢𝐚𝐛𝐥𝐞 𝐢𝐬 𝐩𝐫𝐢𝐦𝐢𝐭𝐢𝐯𝐞 𝐨𝐫 𝐧𝐨𝐧-𝐩𝐫𝐢𝐦𝐢𝐭𝐢𝐯𝐞? -> Primitive (stores single data of single value) #DotNet #AspNetCore #MVC #FullStack #SoftwareEngineering #ProgrammingTips #DeveloperLife #LearnToCode #JavaScript #JS #JavaScriptTips #JSLearning #FrontendDevelopment #WebDevelopment #CodingTips #CodeManagement #DevTools

🚀 Understanding Recursion + Finding Maximum in Nested Arrays (JavaScript) Today I practiced a powerful concept in JavaScript — recursion with nested arrays — and used it to solve a real problem: 👉 Find the maximum number from a deeply nested array 💡 Example: [1, 0, 7, [2, 5, [10], 4]] 🔍 Approach I followed: ✅ Step 1: Used recursion to flatten the nested array If the element is a number → push into result If it’s an array → call the same function again ✅ Step 2: After flattening, used a loop to find the maximum value 🧠 Key Learnings: • Each recursive call creates its own memory (execution context) • Data is temporarily stored in the call stack • The return keyword helps pass results back step by step • Without capturing the returned value, recursion results can be lost • Breaking problems into smaller parts makes complex logic easier ⚡ Final Output: 👉 Maximum number: 10 💬 This exercise really helped me understand: How recursion works internally How data flows through function calls Difference between primitive and reference types #JavaScript #Recursion #ProblemSolving #WebDevelopment #CodingJourney

💡 Interview Question: Understanding Data Types in JavaScript Recently came across an interesting question that tests your fundamental 👇 let a = ''; let b = false; let c = 0; let d = null; let e; let f = {}; let g = []; if (!a) console.log('1') // similarly check for b, c, d, e, f, g 👉 Question: What will be printed in the console for each variable? 🧠 Concept Tested: Truthy vs Falsy values in JavaScript 📌 Falsy values in JS: '' (empty string) false 0 null undefined NaN 📌 Truthy values: {} (empty object) [] (empty array) ✅ Output: 1 2 3 4 5 (Only for a, b, c, d, e → because they are falsy) 🚫 Nothing will be printed for: f = {} g = [] (because they are truthy) 🎯 Key Takeaway: Even empty objects and arrays are considered truthy in JavaScript — a common interview trap! #JavaScript #FrontendDevelopment #WebDevelopment #CodingInterview #InterviewQuestions #Programming #Developers #TechTips #LearnToCode

#2 Hash Tables in JavaScript: Object, Map and WeakMap JavaScript gives us a few different ways to store and look up key-value data. Object, Map, and WeakMap all solve similar problems, but they do so in slightly different ways. In this article, we’ll look at how each of them works, when to use them, and why Object is often treated as a hash-table-like structure in everyday JavaScript code. Here’s the link to the post: https://lnkd.in/d-YPraiU #javascript #node #interview

I was recently asked a classic JavaScript "gotcha" in an interview: "How do you return an object in an arrow function, and why are parentheses required?" It sounds simple But the "Why" is where most developers get tripped up. The Problem: In JavaScript, {} is ambiguous. It can mean an Object Literal OR a Function Block. By default, the JS engine sees a brace after an arrow => and assumes it's a function block. The Result: const getUser = () => { name: 'Chandhan' }; The engine thinks name: is a label and returns undefined. The Fix: Wrap it in parentheses! ({ ... }) The () forces the engine to treat the contents as an expression, not a statement. ✅ const getUser = () => ({ name: 'Chandhan' }); Small syntax, big difference in how the engine parses your code. #JavaScript #WebDevelopment #CodingTips #Angular #Frontend #InterviewPrep

Call, Apply, and Bind in JavaScript Understanding "this" in JavaScript can be tricky. That’s where call, apply, and bind come in. They allow you to control what this refers to. Here’s the difference: • call() → Invokes the function immediately, arguments passed individually • apply() → Invokes immediately, arguments passed as an array • bind() → Returns a new function with this bound (can be called later) Example: const obj = { name: "Tejas" }; function greet(message) { console.log(`${message}, ${this.name}!`); } greet.call(obj, "Hello"); // Hello, Tejas greet.apply(obj, ["Hi"]); // Hi, Tejas const newFn = greet.bind(obj); newFn("Namaskar"); // Namaskar, Tejas Why this matters: • Helps in function borrowing • Useful in event handlers • Commonly asked in interviews • Strengthens understanding of core JavaScript #JavaScript #WebDevelopment #FrontendDevelopment #Coding #Programming

15 JavaScript interview questions. Functions, Scope & Closures. Answer karo comments mein 👇 Functions Q1. What is the difference between function declaration and function expression? Q2. What is an arrow function? How is it different from a regular function? Q3. What is the difference between parameters and arguments? Q4. What are default parameters in JavaScript? Q5. What is a pure function? Q6. What is a higher-order function? Scope Q7. What are the different types of scope in JavaScript? Q8. What is the scope chain in JavaScript? Q9. What is lexical scope? Closures Q10. What is a closure in JavaScript? Q11. What are practical use cases of closures? Q12. What is the classic closure bug in loops — and how do you fix it? Q13. How does React use closures internally? Q14. What is the difference between closure and scope? Q15. What is an IIFE and why is it used? Full answers + code on GitHub 👇 https://lnkd.in/dj72-XEi #JavaScript #JStoReact #InterviewPrep #WebDevelopment #Frontend #30DayChallenge

📘 𝐉𝐚𝐯𝐚𝐒𝐜𝐫𝐢𝐩𝐭 𝐈𝐧𝐭𝐞𝐫𝐯𝐢𝐞𝐰 𝐌𝐨𝐝𝐮𝐥𝐞 (𝐁𝐚𝐬𝐢𝐜) -> Save this checklist, I hope it will be of great use in your next interview revision! 👇 𝐒𝐞𝐜𝐭𝐢𝐨𝐧 1: 𝐁𝐚𝐬𝐢𝐜 𝐉𝐚𝐯𝐚𝐒𝐜𝐫𝐢𝐩𝐭 (𝐓𝐡𝐞 𝐟𝐮𝐧𝐝𝐚𝐦𝐞𝐧𝐭𝐚𝐥𝐬 𝐨𝐟 𝐉𝐚𝐯𝐚𝐒𝐜𝐫𝐢𝐩𝐭) 🎯 𝐈𝐧𝐭𝐞𝐫𝐯𝐢𝐞𝐰 𝐐𝐮𝐞𝐬𝐭𝐢𝐨𝐧𝐬 (𝐄𝐱𝐭𝐫𝐚) 1. 𝐖𝐡𝐲 𝐢𝐬 𝐉𝐚𝐯𝐚𝐒𝐜𝐫𝐢𝐩𝐭 𝐜𝐚𝐥𝐥𝐞𝐝 𝐚 𝐬𝐢𝐧𝐠𝐥𝐞-𝐭𝐡𝐫𝐞𝐚𝐝𝐞𝐝 𝐥𝐚𝐧𝐠𝐮𝐚𝐠𝐞? -> JavaScript can only do one thing at a time. It has only one path (Call Stack). If the work of one line is not completed, it does not go to the next line. 2. 𝐖𝐡𝐚𝐭 𝐢𝐬 𝐞𝐯𝐞𝐧𝐭 𝐥𝐨𝐨𝐩 𝐢𝐧 𝐉𝐚𝐯𝐚𝐒𝐜𝐫𝐢𝐩𝐭? -> Suppose a task comes up in JavaScript that will take time (such as searching for data on the Internet). JavaScript puts that task aside and continues to do other tasks. When the task is completed, the Event Loop brings that data back to the main path. This is the event loop. 3. 𝐖𝐡𝐚𝐭 𝐢𝐬 𝐉𝐈𝐓 (𝐉𝐮𝐬𝐭-𝐈𝐧-𝐓𝐢𝐦𝐞) 𝐜𝐨𝐦𝐩𝐢𝐥𝐚𝐭𝐢𝐨𝐧? -> It compiles at run time and makes it fast. 4. 𝐖𝐡𝐲 𝐉𝐚𝐯𝐚𝐒𝐜𝐫𝐢𝐩𝐭 𝐢𝐬 𝐬𝐨 𝐩𝐨𝐩𝐮𝐥𝐚𝐫 𝐢𝐧 𝐰𝐞𝐛 𝐝𝐞𝐯𝐞𝐥𝐨𝐩𝐦𝐞𝐧𝐭? -> Because it runs everywhere—in browsers, servers (Node.js), mobiles (React Native), and even electronic devices. Its community is very large. 5. 𝐃𝐨𝐞𝐬 𝐉𝐚𝐯𝐚𝐒𝐜𝐫𝐢𝐩𝐭 𝐨𝐧𝐥𝐲 𝐫𝐮𝐧 𝐢𝐧 𝐛𝐫𝐨𝐰𝐬𝐞𝐫𝐬? -> No. Now with Node.js it can be run on PC or server as well. #DotNet #AspNetCore #MVC #FullStack #SoftwareEngineering #ProgrammingTips #DeveloperLife #LearnToCode #JavaScript #JS #JavaScriptTips #JSLearning #FrontendDevelopment #WebDevelopment #CodingTips #CodeManagement #DevTools