Revisiting JavaScript Fundamentals: Closures and Higher-Order Functions

Day 2/30 — JavaScript Fundamentals Refresh ⚙️ Went deeper into execution flow and edge cases that silently break logic. Reinforced how defaults, falsy values, and function returns can mislead even clean-looking code. Small fundamentals, when ignored, compound into production-level bugs. Precision is the real performance win. #JavaScript #EngineeringCraft #FullStackDeveloper #Consistency

Ever tried reading a property that doesn’t exist in JavaScript? No crash. No error. Just… undefined 😄 Most of us do this: if (user.noSuchProperty === undefined) { ... } Works 99% of the time. Until it doesn’t. let obj = { test: undefined }; console.log(obj.test); // undefined console.log("test" in obj); // true ← surprise! The property exists — it just happens to hold undefined. That tiny difference is exactly why the in operator exists. Have you ever been bitten by this gotcha? Or do you still prefer === undefined in everyday code? #JavaScript #CodingTips #WebDevelopment

🟢 Day 17 / 100 – 📌JavaScript Practice 🚀 ✅ Practiced nested arrays using a Tic-Tac-Toe board today. ✅Explored how indexing works in JavaScript by accessing valid, invalid, and negative indexes through the console. • Learned - Errors and undefined values help in understanding how JavaScript actually behaves under the hood. #Day17 #JavaScript #WebDevelopment #FrontendDevelopment

A classic JavaScript trap 🧠 What will this log? const values = [ 1, 1, true, false, 0, '', {}, [] ]; console.log( values.filter( parseInt ) ); console.log( values.filter( Boolean ) ); For the first log, is it [1, 1]? Or something else? What about the second one? Think first. Then run it. The result is not what most people expect 😄 #JavaScript #CodingChallenge #WebDevelopment

Did you know that in JavaScript, `[]` isn't always treated the same way under the hood? 🤯 Depending on how you initialize and manipulate them, your arrays might be optimized contiguous C-structs or slower Hash Maps. Understanding the difference between **Holey Arrays** and **Packed Arrays** can have a significant impact on your application's performance. I just published a deep dive into how V8 handles arrays and how you control which underlying structure you get—often without realizing it. Read the full article here: https://lnkd.in/gqdXFN6s #JavaScript #WebDevelopment #SoftwareEngineering #Performance #V8 #Coding

🚀 #Day 14/100 – 📌JavaScript Logic & Control Flow Today, I focused on understanding how JavaScript makes decisions and handles logic. Topics covered today: ✅Linking JavaScript files and using console.log() ✅Template literals for cleaner output ✅Comparison and logical operators ✅Conditional statements: if, else if, else ✅Nested conditions and truthy vs falsy values ✅switch statements ✅Alerts and prompts for basic user interaction Practicing these concepts helped me understand how real programs control flow and respond to different conditions. Step by step, moving from syntax to thinking in code. Day 14 complete ✅ 👍🏻 #Day14 #JavaScript #ControlFlow #FrontendDevelopment #100DaysOfCode

Today I spent time deeply understanding JavaScript closures and it turned out to be really interesting. Here are a few key takeaways: 1. An inner function can access variables from its outer function 2. Even after the outer function has finished execution, the inner function still holds a reference to those variables 3. If closures are not used properly, they can lead to memory leaks and performance issues, especially under heavy load #JavaScript #Closures #FrontendDevelopment #LearningInPublic #WebDevelopment

https://lnkd.in/diyD-KU3 slice vs splice in JavaScript — a small concept that makes a big difference. Understanding which array methods mutate data and which don’t is crucial for writing predictable and bug-free code, especially in frontend frameworks. Sharing a quick visual breakdown for anyone revising JavaScript fundamentals. Which array method confused you the most when you started? #JavaScriptDevelopers #FrontendDevelopment #ProgrammingBasics #DevelopersOfLinkedIn #ContinuousLearning

I Built My Own Zod-Like Validation Library in JavaScript (schema-validex) I’ve used libraries like Zod and Yup for years, but never really understood how they worked under the hood. So I decided to build my own from scratch. What I learned: - How chainable APIs are designed, ( z.string().min(4) ) - Why immutability makes behavior predictable - TypeScript tricks like generics, infer, and type composition - Returning all errors at once makes validation much cleaner. Full article :- https://lnkd.in/g2cgR_td Github :-  https://lnkd.in/gEsfXH3u npm :- https://lnkd.in/gs2Feiep Sometimes the best way to learn a library is to build one yourself. #JavaScript #TypeScript #WebDev #LearningByDoing

Day 42/100 – An Important JavaScript Concept Many People Ignore Not all performance issues come from bad code. Sometimes they come from too many function calls. 📌 Topic: Debouncing vs Throttling Both are used to control how often a function executes. ✅ Debouncing Runs the function only after a certain time has passed since the last event. Example use cases: • Search input • Form validation 👉 Executes when user stops typing. ✅ Throttling Runs the function at a fixed interval, no matter how many times the event occurs. Example use cases: • Scroll events • Window resize 👉 Executes every X milliseconds. Understanding these concepts helps build faster and smoother applications. Small improvements. Big impact. On to Day 43 🚀 #100DaysOfCode #JavaScript #WebDevelopment #LearningInPublic #Consistency #FrontendDevelopment