Mastering JavaScript splice() and slice() for Interviews

JavaScript interview question that sounds simple — but isn’t: What’s the difference between null, undefined, and NaN? In interviews, clarity matters: null → intentional absence of value undefined → declared but not assigned NaN → invalid number result Even experienced developers get tripped up by: typeof null === "object" NaN === NaN // false This short breaks it down clearly, practically, and interview-first. 👉 If NaN still feels weird, I’ve linked a related breakdown that explains why NaN doesn’t equal itself. #JavaScript #InterviewPreparation #SoftwareEngineering #FrontendDevelopment #WebDevelopment #CodingInterviews #JavaScriptTips #DeveloperLearning #CodebreakDev

🚨 JavaScript Interview Experience 🚨 Recently, I encountered two deceptively simple JavaScript questions during an interview. Many developers write this code daily, but few can explain why it behaves this way: - Automatic Semicolon Insertion - Pre vs Post Increment Interviews don’t just test what you write; they assess how well you understand execution. I'm sharing this to assist fellow developers preparing for frontend and full-stack interviews. #JavaScript #FrontendInterview #FullStackDeveloper #WebDevelopment #InterviewPreparation #JavaScriptTips #CodingInterview #ReactJS #NodeJS #SoftwareEngineering #LearnJavaScript #DeveloperCommunity

Day 15: 5 JavaScript Interview Questions 🚀 Description: These JavaScript interview questions are designed to check your core fundamentals, not just syntax. If you clearly understand concepts like scope, comparison, and events, you can easily crack beginner to mid-level JS interviews. Try answering each question yourself before checking any reference—this builds real confidence. Questions: 1️⃣ What is the difference between var, let, and const in JavaScript? 2️⃣ What is a closure in JavaScript? 3️⃣ What is the difference between == and ===? 4️⃣ What is event bubbling in JavaScript? 5️⃣ What is the difference between undefined and null? Hashtags: #JavaScript #JSInterview #FrontendDeveloper #WebDevelopment #CodingInterview #LearnJavaScript #DeveloperTips #Day15

Type Script Interview question you’ll almost definitely face. I’m starting a short series about real TypeScript challenges from interviews — and we’ll begin with one of the most popular ones: implementing Pick. You’ll often get a task like this: “Recreate the Pick utility type.” The solution is below in the screenshot 👇 At first, it looks simple. But this task checks whether you really understand the fundamentals. It shows how well you understand generics, what keyof really means, how mapped types work, and how TypeScript connects keys to value types. In short, you’re creating a new type by selecting only specific properties — safely and strictly. If you can explain this clearly in an interview, you’re already ahead of many candidates. More Type Script Interview challenges coming soon. #react #frontend #typescript #javascript #javascriptinterview #typescriptinterview #frontendinterview #codinginterview #webdevelopment #programming #softwareengineering #devcareers

Read this if you are preparing for a JavaScript interview If you are preparing for a JavaScript interview, learn Promises for sure. 📌 Almost 40% of async-related questions come directly from Promise concepts. Interviewers expect you to clearly explain: What a Promise is Promise states (pending, fulfilled, rejected) .then(), .catch(), .finally() Promise chaining Error handling in async flows Promises show how well you understand real-world JavaScript, not just syntax. I have attached pdf with this blog to go through promises #JavaScriptInterview #Promises #AsyncJS #FrontendInterview #BackendInterview #FullStackDeveloper #InterviewPrep

⚛️ React Interview Revision Series | Day 1 🚀 Revisiting 𝐑𝐞𝐚𝐜𝐭.𝐣𝐬 𝐟𝐮𝐧𝐝𝐚𝐦𝐞𝐧𝐭𝐚𝐥𝐬 as part of my interview preparation. 📌 Topics revised today: • What is React & why it is used • Component-based architecture • Difference between React and traditional JavaScript UI handling • Overview of Virtual DOM Focusing on clarity of concepts that are commonly discussed in React interviews. Along with React, I’m also revising: ☕ Core Java 🧠 DSA Preparing to perform better in technical interviews. Any interview tips related to this topic?😊 #ReactJS #ReactInterview #FrontendDevelopment #WebDevelopment #PlacementPreparation

🚀 React Interview Prep | Debounce & Throttle (Hands-on) Recently, I solved a React mock interview question asked by Anurag Singh (ProCodrr – YouTube), focused on implementing Debounce and Throttle from scratch using React Hooks. 💡 What I implemented: Normal click handling Debounce logic using useCallback and useRef Throttle logic using useCallback and useRef Practical comparison of how each behaves on rapid clicks 🧠 Key Learnings: How closures work inside debounce/throttle Why useRef is preferred over useState for mutable values When to use debounce vs throttle in real-world applications This exercise helped me deeply understand performance optimization patterns in React — something interviewers often look for beyond theory. Huge shout-out to Anurag Singh bhai for creating such mock interviews on YouTube. They are extremely helpful for interview preparation 🙌 #ReactJS #JavaScript #FrontendDevelopment #WebPerformance #Debounce #Throttle #ReactHooks #InterviewPreparation #LearningByBuilding

⚛️ Top 150 React Interview Questions – 20/150 📌 Topic: State vs. Props in React This question is a React interview classic — and many candidates still get it wrong. 🔑 Core difference (remember this line): State is internal and changeable Props are external and read-only 🧠 Think of it this way: State is like your memory or personality — it lives inside the component and can be changed by the component itself. Props are like your clothes — they are given by the Parent. You don’t change them; you receive new ones. ❓ Why do we need both? Because a component must: Manage its own private data (State) Receive data and instructions from its Parent (Props) This separation keeps React components modular, predictable, and reusable. ⚖️ State vs. Props (Quick Comparison) Source State: Defined inside the component Props: Passed from the Parent Mutability State: Mutable (via setState / useState) Props: Immutable (read-only for the Child) Ownership State: Owned by the component Props: Owned by the Parent Re-render State: Re-renders when state changes Props: Re-renders when the Parent updates them 🌍 Real-world example Imagine a Counter component inside a Dashboard: Props: The Dashboard passes color="blue" → Counter uses it for styling → Counter cannot change it to red by itself State: Counter has count as state → Clicking a button calls setCount(count + 1) → Counter updates its own number 📝 One-line summary: State: “I manage this myself.” Props: “My parent told me this.” 👇 Comment “React” if this series is helping you 🔁 Share with someone preparing for React interviews #ReactJS #FrontendDevelopment #ReactInterview #JavaScript #WebDevelopment #LearningInPublic #Top150ReactQuestions

In JavaScript interviews, one task comes up surprisingly often: “Write a memoized function.” At first glance it looks simple, but interviewers usually want to see that you understand the core idea, not just syntax. The main concept is always the same: 1. Wrap the original function 2. Store results in a cache 3. Use function arguments as a cache key Return cached data instead of recalculating. I’ve added an example on the screenshot — it’s short and shows exactly how it works. The key thing interviewers look for is why this works: same input → same output → no need to recompute. Have you had this task in interviews as well?

🔥 React Interview Questions — Real-World & Practical (MNC Focus) 🧠 Preparing for React interviews? Most interviews today don’t test theory — they test how React works in real projects. 📘 This series covers: How React works internally (rendering, reconciliation, re-renders) Hooks deep dive (useEffect, useLayoutEffect, useMemo, useCallback, useRef) Real interview bugs & scenarios asked in MNCs Performance optimization & common mistakes Practical questions based on actual project experience 🎯 Perfect for: Frontend Developers React Interview Preparation Product & Service-based company interviews 📥 Follow along for clear explanations and real interview insights, and save this post for quick reference during prep. #ReactJS #FrontendDeveloper #ReactInterview #JavaScript #WebDevelopment #FrontendInterview #MNCInterviews #ReactHooks #InterviewPreparation #SoftwareEngineer