JavaScript Data Structures: Arrays, Objects, Maps, Sets

Built an efficient LRU Cache from scratch using JavaScript. Key highlights of the implementation: Designed a custom Doubly Linked List for O(1) insertions and deletions Used a HashMap to achieve constant-time access Ensured optimal eviction strategy by always removing the least recently used node Maintained strict O(1) time complexity for both get and put operations Performance: Runtime: 102 ms (faster than ~57% of submissions) Memory: 113.67 MB This problem reinforced how combining data structures (HashMap + DLL) leads to highly optimized systems — a pattern widely used in real-world caching systems like databases and browsers. Continuing to focus on writing clean, efficient, and scalable code. #DataStructures #Algorithms #JavaScript #SystemDesign #Coding

I recently implemented my first Linked List from scratch in JavaScript — no libraries, just raw pointer manipulation. This wasn’t just about writing code; it forced me to understand how data structures actually work under the hood. Here’s what I built: A custom Node structure with value and next pointers Core operations: addAtHead addAtTail addAtIndex deleteAtIndex get What made this interesting wasn’t the syntax — it was the edge cases and pointer management: Handling insertions at head vs tail Maintaining consistent length Avoiding broken references during insertion/deletion Fixing off-by-one errors in traversal Biggest takeaway: Linked Lists are simple in theory, but brutally unforgiving if your pointer logic is even slightly off. This exercise sharpened how I think about: Data structure integrity Boundary conditions Writing predictable, bug-resistant logic Still refining and testing edge cases — but this was a solid step forward. #JavaScript #DataStructures #LinkedList #Coding #SoftwareEngineering #LearningInPublic

🚀 Day 9| JavaScript Today I explored JavaScript Foundations: Primitive Data Types & Operations — the building blocks of programming. 📌 Key concepts I learned: 🔹 Primitive Data Types • Number & BigInt → Used for numeric values and large integers • Boolean → Represents true or false (used in decision making) • Null & Undefined → Represent empty or uninitialized values 🔹 Operations in JavaScript • Arithmetic operations (+, -, *, /) • Logical operations (&&, ||, !) • Comparison operations (==, ===, >, <) ⚙️ I also understood how JavaScript performs computational actions to process and manipulate data effectively. 💡 Learning these fundamentals is important to build strong problem-solving skills and write efficient code. Step by step, I’m strengthening my JavaScript basics and programming logic. 💻✨ #JavaScript #WebDevelopment #FrontendDevelopment #CodingJourney #LearningInPublic #DeveloperJourney #ProgrammingBasics

Ever changed a variable in JavaScript only to realize you accidentally broke the original data too? 🤦♂️ That’s the classic Shallow vs. Deep Copy trap. Here is the "too long; didn't read" version: 1. Shallow Copy (The Surface Level) When you use the spread operator [...arr] or {...obj}, you’re only copying the top layer. The catch: If there are objects or arrays inside that object, they are still linked to the original. Use it for: Simple, flat data. 2. Deep Copy (The Full Clone) This creates a 100% independent copy of everything, no matter how deep the nesting goes. The easy way: const copy = structuredClone(original); The old way: JSON.parse(JSON.stringify(obj)); (Works, but it’s buggy with dates and functions). The Rule of Thumb: If your object has "layers" (objects inside objects), go with a Deep Copy. If it’s just a basic list or object, a Shallow Copy is faster and cleaner. Keep your data immutable and your hair un-pulled. ✌️ #Javascript #WebDev #Coding #ProgrammingTips

var vs let vs const — The Real Differences If you're still reaching for `var` by default, this one's for you. Three keywords. Three very different behaviors. var • Function-scoped (ignores block scope) • Can be redeclared in the same scope • Hoisted and initialized as undefined • Legacy. Avoid in new code. let • Block-scoped • Can be reassigned, cannot be redeclared • Hoisted but not initialized (Temporal Dead Zone) • Use it when a value needs to change. const • Block-scoped • Cannot be reassigned or redeclared • Same hoisting behavior as let • Use it by default. Your future self will thank you. Rule of thumb: → const by default → let when you must reassign → var — don't Next post: Data Types — all seven, with the typeof null trap. Follow the series. #JavaScript #WebDevelopment #Frontend #CleanCode #NodeJS #SoftwareEngineering #WebDev #CodingTips #ES6 #LearnJavaScript #Programming #Coder #FullStackDeveloper #ReactJS #TypeScript #100DaysOfCode #DeveloperCommunity #TechTips #CodeNewbie #ProgrammingLife

Cracking the Logic: Finding the First Occurrence! I’ve always believed that the best way to master a programming language is by building your own logic from scratch before jumping into built-in methods. Today, I worked on a classic problem: Finding the starting index of a substring within a string. The Task: Given two strings, identify the index where the second string first appears in the first one. For example: Input: ("sadbutsad", "sad") ➔ Output: 0 My Approach: Array Transformation: Split the strings into arrays to iterate through each character. Filtering Logic: Used the .filter() method to check if the main string's characters exist in the target substring using .includes(). Index Tracking: Pushed the matching indices into a temporary array. Result Extraction: Sliced the first element to get the exact starting point. The Code: JavaScript function findIdStr(a, b) { const repetArrId = [] const y = a.split('') const x = b.split('') y.filter((v, idx) => { if (x.includes(v)) { repetArrId.push(idx) } }) const result = repetArrId.slice(0, 1) console.log("Starting Index:", result[0]) } findIdStr("sadbutsad", "sad") // Output: 0 While JavaScript offers built-in tools like .indexOf(), breaking it down manually helps in understanding how data flows and how loops work under the hood. I’m curious—how would you optimize this logic? Let’s discuss in the comments! #JavaScript #WebDevelopment #ProblemSolving #CodingJourney #SoftwareEngineering #LogicBuilding #JSIndex

#Day13 Set is a powerful built-in data structure in JavaScript that stores only unique values while maintaining insertion order. During my #Backend development track in Mentorship for Acceleration, I deepened my understanding of Sets and explored how to perform essential set operations. Union, Intersection, and Difference. While arrays are flexible, they allow duplicates and have slower lookup times for membership checks. Sets solve these limitations elegantly. Today, I practiced creating Sets and implementing the three core operations that are frequently used in real-world applications. Key Set Operations I Implemented: => Union: Merges all elements from two Sets while automatically removing duplicates, producing a single comprehensive collection. => Intersection: Extracts only the values that exist in both Sets, making it ideal for finding common elements between datasets. => Difference: Returns elements that are present in the first Set but not in the second, which is particularly useful for comparison and data filtering. Mastering Sets has encouraged me to think more intentionally about data structures. Choosing the right one, whether an Array, Object, Map, or Set — significantly impacts code performance, readability, and maintainability. This session reinforced that writing good code is not just about logic, but also about selecting the most appropriate tools for the job. How often do you find yourself using Sets in your JavaScript projects? #M4ACELearningChallenge #LearningInPublic #JavaScript

Node.js Worker Threads: True Multi-Threading for Your JavaScript Code Node.js is recognized for its efficient handling of I/O through the Event Loop and the UV_THREADPOOL for system-level tasks. However, when JavaScript code becomes the bottleneck, Worker Threads are essential. 🧠 Core Concepts: - Isolated Execution: Each worker operates in its own V8 instance with separate memory, functioning like lightweight parallel Node.js instances. - True Parallelism: Unlike the Event Loop, which is concurrent, Worker Threads enable parallel execution by utilizing multiple CPU cores. - Message-Based Communication: Workers communicate via postMessage(), ensuring no shared state by default, which reduces race conditions. 🛠 When to use them? - Avoid using Worker Threads for I/O, as the Event Loop is more efficient for that. Instead, utilize them for CPU-bound tasks that could otherwise "freeze" your app: - Heavy Math: Complex calculations or data science in JavaScript. - Data Parsing: Transforming large JSON or CSV files. - Image/Video: Processing buffers or generating reports. Key Takeaway: The Thread Pool manages system tasks, while Worker Threads enhance the performance of your JavaScript code. #NodeJS #Backend #Javascript #WebDev #SoftwareEngineering #Performance

🚀 #Angular Question: #switchMap vs #mergeMap vs #concatMap If you're learning #Angular or #RxJS, these three operators can be confusing at first. Here’s a simple explanation with real-world application examples 👇 🔹 switchMap — Cancels Previous Request 👉 Best Example: Search Bar / Auto Suggest User types quickly in search box: "A" → API call starts "An" → Previous call cancelled "Angular" → Only latest call runs ✅ Used in: • Search functionality • Auto suggestions • Live filtering 🔹 mergeMap — Runs Requests in Parallel 👉 Best Example: Loading Dashboard Data When dashboard loads: Load Users API Load Orders API Load Notifications API All API calls run at the same time 🚀 ✅ Used in: • Dashboard data loading • Multiple independent API calls • Upload multiple files 🔹 concatMap — Runs Requests One by One 👉 Best Example: Saving Form Data Step-by-Step Multi-step form: Save Step 1 Save Step 2 Save Step 3 Each request waits for previous one to finish ✅ ✅ Used in: • Multi-step forms • Sequential API calls • Order processing 🎯 Easy Memory Trick • switchMap → Cancel previous • mergeMap → Run parallel • concatMap → Run in order These are very common in Angular + RxJS interviews and real projects. Which one do you use the most? 👇 #Angular #RxJS #FrontendDevelopment #AngularDeveloper #WebDevelopment #JavaScript #SoftwareEngineering #Programming