Valid Palindrome and Anagram Solutions in JavaScript

🚀 JavaScript Last-Minute Cheat Sheet — Perfect Before Interviews & Coding Rounds 🔥 Variables & Scope • "let" & "const" over "var" • Block scope matters • Avoid global variables ⚡ Functions • Arrow functions → shorter syntax • Default parameters save time • Closures = function + lexical scope 🧠 Async JavaScript • Callbacks → Promises → "async/await" • Use "try...catch" for error handling • "Promise.all()" for parallel execution 📦 Arrays & Objects • "map()", "filter()", "reduce()" = must know • Spread "..." & Destructuring simplify code • Optional chaining "?." prevents crashes 🎯 DOM & Events • "querySelector()" is your best friend • Event delegation improves performance • Debounce & throttle for optimization 💡 Pro Tip Understand concepts, not just syntax. Clean code + problem-solving mindset = real JavaScript mastery. Learn more From w3schools.com ✨ #JavaScript #WebDevelopment #FrontendDeveloper #CodingInterview #100DaysOfCode

Easter tree? 🌳 🪺 It’s very similar to the LeetCode 103 problem (Binary Tree Zigzag Level Order Traversal), but this time we don’t need to return an array of values. Instead, we need to mutate the tree and apply the changes directly to the nodes. So we traverse the tree level by level, collect all the nodes on each level, and then reverse the values on every odd level. We also have to remember that we don’t want to change the order of the nodes themselves, only their values. That’s why the built-in reverse() method isn’t enough here. We need a custom algorithm that swaps the values directly (Two pointers). #javascript #interview #node

🚀🔥 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

#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

🚀 JavaScript Last-Minute Cheat Sheet — Perfect Before Interviews & Coding Rounds 🔥 Variables & Scope • "let" & "const" over "var" • Block scope matters • Avoid global variables ⚡ Functions • Arrow functions → shorter syntax • Default parameters save time • Closures = function + lexical scope 🧠 Async JavaScript • Callbacks → Promises → "async/await" • Use "try...catch" for error handling • "Promise.all()" for parallel execution 📦 Arrays & Objects • "map()", "filter()", "reduce()" = must know • Spread "..." & Destructuring simplify code • Optional chaining "?." prevents crashes 🎯 DOM & Events • "querySelector()" is your best friend • Event delegation improves performance • Debounce & throttle for optimization 💡 Pro Tip Understand concepts, not just syntax. Clean code + problem-solving mindset = real JavaScript mastery. Learn More From w3schools.com , JavaScript Mastery ✨ Follow ABDUL REHMAN ♾️ For More Usefull Contents 🔥 #JavaScript #WebDevelopment #FrontendDeveloper #CodingInterview #100DaysOfCode

JavaScript Interview Question: How do you cancel API requests in JavaScript? Answer: Using AbortController. Example: 𝘤𝘰𝘯𝘴𝘵 𝘤𝘰𝘯𝘵𝘳𝘰𝘭𝘭𝘦𝘳 = 𝘯𝘦𝘸 𝘈𝘣𝘰𝘳𝘵𝘊𝘰𝘯𝘵𝘳𝘰𝘭𝘭𝘦𝘳() 𝘧𝘦𝘵𝘤𝘩("/𝘢𝘱𝘪/𝘥𝘢𝘵𝘢", {  𝘴𝘪𝘨𝘯𝘢𝘭: 𝘤𝘰𝘯𝘵𝘳𝘰𝘭𝘭𝘦𝘳.𝘴𝘪𝘨𝘯𝘢𝘭 }) // 𝘤𝘢𝘯𝘤𝘦𝘭 𝘳𝘦𝘲𝘶𝘦𝘴𝘵 𝘤𝘰𝘯𝘵𝘳𝘰𝘭𝘭𝘦𝘳.𝘢𝘣𝘰𝘳𝘵() Explanation: AbortController allows you to cancel ongoing requests. Useful for: 1. search inputs (cancel previous queries) 2. component unmount 3. preventing race conditions Without it, outdated responses may overwrite newer data. Follow-up: Have you ever faced race condition bugs in API calls? #javascript #WebDevelopment #AsyncProgramming #FrontendDevelopment

Your string methods work, but do you know HOW? Most developers use includes(), trim(), split() without understanding the logic underneath. I just published a guide where I BUILD each method from scratch — because writing a polyfill teaches you more than reading docs ever will. Topics covered: What string methods actually do (conceptually) Why polyfills matter for compatibility Custom implementations you can learn from 5 real interview problems solved The breakthrough: Once you can build includes() or trim() yourself, every string method becomes intuitive. 🔗 Read here: https://lnkd.in/gaFVmt4H More JavaScript on my Hashnode: https://lnkd.in/gAwxuryw Learning from @Hitesh Choudhary @Piyush Garg @ChaiCode #JavaScript #StringMethods #WebDevelopment

🚀 From Arrays to Efficiency: Mastering Set in JavaScript Today I solved the “Unique Rows in Boolean Matrix” problem using one simple yet powerful concept — Set. At first glance, the problem looks like a typical nested loop challenge. But instead of going brute force, I leveraged Set to achieve a clean and optimal solution. 💡 Key Idea: Convert each row into a string and store it in a Set to automatically handle duplicates. ✨ Why this is powerful: Eliminates duplicates in O(1) lookup time Avoids unnecessary nested loops Keeps the solution clean and readable 📊 Complexity: Time: O(n × m) Space: O(n × m) 🔥 Takeaway: Sometimes, the difference between an average solution and an optimal one is just knowing the right data structure. Today it was Set. Tomorrow, it could be something else. 💬 Curious: Where else have you used Set to simplify a problem? #JavaScript #DSA #CodingInterview #WebDevelopment #ProblemSolving #100DaysOfCode

📘 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

📘 𝐉𝐚𝐯𝐚𝐒𝐜𝐫𝐢𝐩𝐭 𝐈𝐧𝐭𝐞𝐫𝐯𝐢𝐞𝐰 𝐌𝐨𝐝𝐮𝐥𝐞 (𝐁𝐚𝐬𝐢𝐜) -> Save this checklist, I hope it will be of great use in your next interview revision! 👇 𝐒𝐞𝐜𝐭𝐢𝐨𝐧 7: 𝐒𝐭𝐫𝐢𝐧𝐠 1.𝐖𝐡𝐚𝐭 𝐢𝐬 𝐬𝐭𝐫𝐢𝐧𝐠? -> String is a sequence of characters (text data). A string is a collection of one or more characters. 2.𝐇𝐨𝐰 𝐭𝐨 𝐝𝐞𝐜𝐥𝐚𝐫𝐞 𝐬𝐭𝐫𝐢𝐧𝐠? -> In JavaScript, it can be written in three ways: 1. Single quote ('data') 2. Double quote ("data") 3. Backtick (`data`) — this is called a template literal. 3.𝐒𝐭𝐫𝐢𝐧𝐠 𝐃𝐞𝐜𝐥𝐚𝐫𝐞 𝐒𝐩𝐞𝐜𝐢𝐚𝐥 𝐰𝐚𝐲 𝐨𝐫 𝐒𝐩𝐞𝐜𝐢𝐚𝐥 𝐩𝐮𝐫𝐩𝐨𝐬𝐞 𝐬𝐭𝐫𝐢𝐧𝐠? -> We usually write let name = "XYZ" (this is called String Primitive). But when we do new String("XYZ"), it creates an Object. Creating a string in this way should be avoided because it takes up more memory and slows down performance. 4.𝐒𝐭𝐫𝐢𝐧𝐠 𝐂𝐡𝐞𝐜𝐤 𝐭𝐲𝐩𝐞? -> typeof variableName 5.𝐒𝐭𝐫𝐢𝐧𝐠 𝐥𝐞𝐧𝐠𝐭𝐡 𝐂𝐡𝐞𝐜𝐤? -> variableName.length 6.𝐒𝐭𝐫𝐢𝐧𝐠 𝐀𝐜𝐜𝐞𝐬𝐬 𝐢𝐧𝐝𝐞𝐱? -> variableName[indexNumber] 7.𝐖𝐡𝐚𝐭 𝐢𝐬 𝐞𝐦𝐩𝐭𝐲 𝐬𝐭𝐫𝐢𝐧𝐠? -> Which does not contain any character or space (""). 8.𝐖𝐡𝐞𝐧 𝐭𝐨 𝐮𝐬𝐞 𝐞𝐦𝐩𝐭𝐲 𝐬𝐭𝐫𝐢𝐧𝐠? -> To give initial value (form, input field etc.). It is usually used during initialization of a variable or to check if the user input box is empty. 9.𝐒𝐭𝐫𝐢𝐧𝐠 𝐢𝐬 𝐢𝐦𝐦𝐮𝐭𝐚𝐛𝐥𝐞 𝐨𝐫 𝐦𝐮𝐭𝐚𝐛𝐥𝐞? -> Yes (cannot be changed). String is immutable or immutable. 10.𝐒𝐭𝐫𝐢𝐧𝐠 𝐦𝐞𝐭𝐡𝐨𝐝𝐬? -> toLowerCase(), toUpperCase(), trim(), slice(), split(), join(), concat(), includes() 11.𝐒𝐭𝐫𝐢𝐧𝐠 𝐜𝐨𝐧𝐜𝐚𝐭𝐞𝐧𝐚𝐭𝐢𝐨𝐧? -> +, concat() #DotNet #AspNetCore #MVC #FullStack #SoftwareEngineering #ProgrammingTips #DeveloperLife #LearnToCode #JavaScript #JS #JavaScriptTips #JSLearning #FrontendDevelopment #WebDevelopment #CodingTips #CodeManagement #DevTools