Muhammad Mubazar Qureshi 🖥️’s Post

Closures looked magical when I first learned JavaScript. Now I see them as one of the most practical tools in the language. A closure is just a function carrying the variables it needs from its surrounding scope. Simple idea, huge impact. You use closures in: event handlers React hooks debounce functions middleware private state factory functions The hard part is not the definition. The hard part is knowing when that captured value becomes stale. That one mistake explains many weird bugs: "Why is this state old?" "Why did this callback run with previous data?" "Why is my timer behaving strangely?" Deep JavaScript is mostly learning where values live, how long they live, and who can still access them. #JavaScript #FrontendDevelopment #WebDevelopment

Today I finally understood how JavaScript actually stores data in memory — and it changed the way I look at code. Earlier, I used to just write variables and functions without thinking much about what’s happening behind the scenes. But now it makes a lot more sense: Primitive values (like numbers, strings, booleans) are stored directly in memory Reference types (like arrays and objects) are stored differently — the variable holds a reference, not the actual value That’s why things like this behave unexpectedly sometimes: Copying objects doesn’t create a real copy Changing one reference can affect another Understanding this cleared up a lot of confusion I had while debugging. Still learning, but this felt like a small breakthrough Hitesh Choudhary Piyush Garg Chai Code #JavaScript #WebDevelopment #100DaysOfCode #LearningInPublic

shipped wyscan v1.4.0-beta today. TypeScript and JavaScript agentic systems are now fully supported, on par with Python. for context, wyscan is a static analysis tool that scans your agent codebase and surfaces AFB04 violations before they hit production. AFB04 is the unauthorized action boundary: the point where an agent executes something it was never supposed to be allowed to do. tool calls without policy gates, execution paths with no authorization check, actions that bypass the enforcement layer entirely. wyscan finds them at the code level, before your agent is ever deployed. Until now, that coverage was Python-only. if your stack was TypeScript or JavaScript - LangChain.js, Mastra, any TS/JS agent framework - you were flying blind. v1.4.0-beta closes that gap. wyscan now scans TS/JS agentic systems the same way it handles Python. same detection logic, same CEE-formatted output, same class of findings. if an unauthorized action boundary violation exists in your agent code, it surfaces, regardless of whether you're on the Python or JS/TS side. this release also fixes and upgrades several Python-side limitations from earlier versions. the output is cleaner, the detection is more accurate, and there's less noise in the results. this is beta, so there will be rough edges. but the core detection works, the findings are real, and the coverage is there. if you're building agentic systems in TS or JS and want to know what wyscan finds in your stack, now you can. https://lnkd.in/dny8Q5tF #buildinpublic #agentsecurity #aiagents #llmsecurity #opensource #wyscan #plarix #typescript #javascript #agentic

🚀 Day 4/30 – JavaScript Challenge Solved: Counter II (LeetCode 2665) Today’s problem was all about understanding closures and how functions can maintain their own state in JavaScript. What I learned: 1.How closures help preserve variable values across function calls 2.Creating multiple operations (increment, decrement, reset) using a single function 3.Clean use of arrow functions for concise code Approach: I created a function that stores the initial value and returns an object with three methods: 1.increment() -> increases value 2.decrement() -> decreases value 3.reset() -> resets to initial value All of this works because of closure, where the inner functions still remember the variable n. Key Insight: Closures are powerful when you need to encapsulate data and control how it’s modified — a very common pattern in real-world JavaScript applications. Consistency is the real game here 🔥 Let’s keep building, one day at a time. #Day4 #30DaysOfCode #JavaScript #WebDevelopment #CodingChallenge #LeetCode #Closures #LearningJourney

🚀 Day 968 of #1000DaysOfCode ✨ Types of Loops in JavaScript (Explained Simply) Loops are one of the most fundamental concepts in JavaScript — but choosing the right one can make a big difference in your code. In today’s post, I’ve explained the different types of loops in JavaScript in a simple and practical way, so you can understand when to use each one. From `for` and `while` to `for...of` and `for...in`, each loop has its own purpose depending on how you’re working with data. Using the right loop not only makes your code cleaner but also improves readability and performance in many cases. This is one of those basics that every developer uses daily — but mastering it helps you write much better code. If you’re working with arrays, objects, or complex data structures, this is something you should be confident about. 👇 Which loop do you use the most in your day-to-day coding? #Day968 #learningoftheday #1000daysofcodingchallenge #FrontendDevelopment #WebDevelopment #JavaScript #React #CodingCommunity #JSBasics

🚀 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

The JavaScript toolchain is getting a full Rust rewrite, one piece at a time. Oxc is doing the most ambitious version. Oxc (The JavaScript Oxidation Compiler) is a collection of high-performance tools for JavaScript and TypeScript, all written in Rust and designed to share the same parser and AST: → Parser: fastest JS/TS parser available, 3–5x faster than SWC → Linter (oxlint): replaces ESLint, runs in parallel, 50–100x faster → Resolver: module resolution for bundlers → Transformer: replaces Babel for most transforms → Minifier: in progress, targeting terser replacement The key design decision: all tools share one AST. Parse once, lint + transform + analyze in the same pass. No redundant parsing across your build pipeline. oxlint is already production-ready and ships as a standalone binary. You can run it alongside ESLint today, it's designed to catch the 90% of rules that matter in milliseconds, letting you keep complex custom ESLint rules only where needed. Vite 6 integrated Oxc's resolver. Rolldown (the Rust Rollup rewrite) uses Oxc's parser. The whole bundler ecosystem is converging on it. 🔗 npx oxlint@latest 📂 https://lnkd.in/d3yxBVUC 📖 https://oxc.rs #JavaScript #TypeScript #Rust #Oxc #OpenSource

🚀 Day 67 | JavaScript Loops & Array Iteration Today I practiced JavaScript loops and working with arrays of objects 💻 🔹 What I Worked On: • Iterated through array of objects using for loop • Printed all elements and accessed object properties like loc • Used loop with step increment (i += 2) to print alternate values • Practiced reverse counting using for and while loops • Used forEach() for cleaner array iteration 💡 Key Learning: • Arrays of objects are very common in real-world applications • Loop conditions must be handled carefully (i < length vs <= length) • forEach() is simple and readable for iteration • Multiple ways to loop → choose based on requirement 🔥 Takeaway: 👉 Mastering loops is key to handling data efficiently in JavaScript Consistency is improving logic step by step 🚀 #Day67 #JavaScript #Loops #ArrayIteration #ProblemSolving #CodingJourney #10000Coders #WebDevelopment #SravanKumarSir

🔥 JavaScript Devs — Why “Undefined” Causes So Many Real Bugs Hey devs 👋 One of the smallest values in JavaScript… Creates some of the biggest headaches 😅 👉 undefined often appears when: Missing API fields Wrong property names Unreturned functions Async race conditions 💥 Then suddenly: Cannot read property of undefined 💡 What helps: ✔ Optional chaining ?. ✔ Default values ?? ✔ Strong typing (TypeScript) ✔ Better API contracts ⚡ Senior insight: “Most runtime bugs start with assumptions.” Never assume data exists. What bug did undefined cause for you? #javascript #typescript #programmingtips #webdevelopment #frontenddeveloper #backenddeveloper #codingbestpractices #softwareengineering #jsbugs #cleanCode

Day 66 | JavaScript Loops & Array Iteration Today I practiced JavaScript loops and working with arrays of objects🧑🏻💻 - What I Worked On: •Iterated through array of objects using for loop •Printed all elements and accessed object properties like loc •Used loop with step increment (i += 2) to print alternate values •Practiced reverse counting using for and while loops •Used forEach() for cleaner array iteration 💡 Key Learning: •Arrays of objects are very common in real-world applications •Loop conditions must be handled carefully (i < length vs <= length) •forEach() is simple and readable for iteration •Multiple ways to loop → choose based on requirement Takeaway: Mastering loops is key to handling data efficiently in JavaScript Consistency is improving logic step by step #Day66 #JavaScript #Loops #Arraylteration #ProblemSolving #CodingJourney #10000Coders #WebDevelopment #SravanKumarSir