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
Understanding Closures in JavaScript
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🚀 𝐃𝐚𝐲 𝟓/𝟏𝟓 𝐨𝐟 𝐌𝐲 𝐉𝐚𝐯𝐚𝐒𝐜𝐫𝐢𝐩𝐭 𝐋𝐞𝐚𝐫𝐧𝐢𝐧𝐠 𝐒𝐞𝐫𝐢𝐞𝐬 Today I learned about Loops in JavaScript 🔁 👉 Loops are used to run a block of code multiple times. 📌 Types of Loops: 1️⃣ for loop for (let i = 0; i < 5; i++) { console.log(i); } 2️⃣ while loop let i = 0; while (i < 5) { console.log(i); i++; } 👉 Both loops do the same thing, but the use depends on the situation. 📌 Key Difference: for loop → when you know how many times to run while loop → when condition-based looping is needed Loops make coding faster and more efficient 💻✨ 💬 Question: Which loop do you find easier — for or while? Let’s learn together 🚀 #JavaScript #WebDevelopment #LearningInPublic #Day5 #FrontendDevelopment
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🚀 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
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🚀 I finally understood Closures in JavaScript (and it was confusing at first) At first, I thought every function call resets variables… But closures completely changed my understanding. Here’s the simple idea 👇 👉 A closure is when a function remembers variables from its outer function, even after the outer function has finished. Example: function outer() { let count = 0; return function () { count++; console.log(count); }; } const counter = outer(); counter(); // 1 counter(); // 2 counter(); // 3 💡 Why does this work? Because the inner function “remembers” the variable count. Even though outer() has already executed, the value is not lost. 🔥 Key takeaway: Normal functions → reset values every time Closures → keep values alive This concept is widely used in: ✔️ Counters ✔️ Data hiding ✔️ Event handlers Still practicing and improving my JavaScript fundamentals 💻 Have you ever struggled with closures? 🤔 #JavaScript #WebDevelopment #MERNStack #Coding #Learning #100DaysOfCode
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🚀 𝐃𝐚𝐲 𝟒 𝐨𝐟 𝐌𝐲 𝐉𝐚𝐯𝐚𝐒𝐜𝐫𝐢𝐩𝐭 𝐋𝐞𝐚𝐫𝐧𝐢𝐧𝐠 𝐒𝐞𝐫𝐢𝐞𝐬 Today I learned about if-else (Conditions) in JavaScript 💡 👉 Conditions are used to make decisions in code. 📌 Syntax: if (condition) { // code runs if condition is true } else { // code runs if condition is false } 📌 Example: let age = 18; if (age >= 18) { console.log("You can vote"); } else { console.log("You cannot vote"); } 👉 Also learned about: else if → check multiple conditions 📌 Example: let marks = 75; if (marks > 90) { console.log("Grade A"); } else if (marks > 60) { console.log("Grade B"); } else { console.log("Grade C"); } 👉 Conditions help in building real-world logic 💻✨ 💬 Question: Have you used if-else in any project yet? Let’s learn together 🚀 #JavaScript #WebDevelopment #LearningInPublic #Day4 #FrontendDevelopment
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🚀 𝐃𝐚𝐲 𝟔/𝟏𝟓 𝐨𝐟 𝐌𝐲 𝐉𝐚𝐯𝐚𝐒𝐜𝐫𝐢𝐩𝐭 𝐋𝐞𝐚𝐫𝐧𝐢𝐧𝐠 𝐒𝐞𝐫𝐢𝐞𝐬 Today I learned about Functions in JavaScript 💡 👉 Functions are reusable blocks of code They help us avoid repeating the same code again and again. 📌 Syntax: function greet() { console.log("Hello!"); } 👉 Calling the function: greet(); // Hello! 📌 Functions with parameters: function greet(name) { console.log("Hello " + name); } greet("Kanishka"); 👉 Functions make code cleaner, reusable, and easy to manage 💻✨ 💬 Question: Have you started using functions in your projects? Let’s learn together 🚀 #JavaScript #WebDevelopment #LearningInPublic #Day6 #FrontendDevelopment
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🚀 I was exploring what’s new in JavaScript (ECMAScript 2025), and I thought of sharing a few features that I found interesting. Here’s the first one 👇 👉 Iterator Helpers We often chain array methods like this: const prices = [5, 12, 8, 20, 3, 15]; const result = prices .map(p => p + 2) .filter(p => p >= 10) .slice(0, 2); This creates multiple intermediate arrays in memory. With Iterator Helpers: 👉 No intermediate arrays 👉 Lazy execution (only processes what’s needed) 👉 Stops early once it gets required results As someone who mostly works on frontend, this felt a bit subtle at first, but the performance benefit makes it quite interesting.
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👉 Click here to read the full article: https://lnkd.in/gtqtAys7 🚀 Error Handling in JavaScript (Try, Catch, Finally) Understanding error handling is a must-have skill for every JavaScript developer. In this article, I cover: ✅ What errors are in JavaScript ✅ try & catch blocks ✅ finally block usage ✅ Throwing custom errors ✅ Why error handling matters Also included: 📌 Runtime error examples 📌 Graceful failure concepts 📌 Debugging benefits 📌 Try → Catch → Finally flow If you're learning JavaScript or backend development, this will help you write more reliable code. 🙏 Special thanks to 👉 Hitesh Choudhary Sir 👉 Piyush Garg Sir 👉 Chai Aur Code #JavaScript #WebDevelopment #BackendDevelopment #Coding #ErrorHandling
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I did a deep dive 🔍 into JavaScript fundamentals and it reminded me why mastering the basics is non-negotiable in engineering. Here's what I explored: ▸ Variables & Hoisting — why let and const replaced var, and what the Temporal Dead Zone actually means ▸ Control Flow — from ternary operators to early return patterns that keep code clean ▸ Functions — closures, higher-order functions, and why JS treats functions as first-class citizens ▸ Arrays & Objects — the iteration methods (map, filter, reduce) every developer needs in their toolkit The more I revisit fundamentals, the more I realize how much of modern JavaScript is built on these exact concepts. Frameworks come and go — but a solid grasp of closures, scope, and data structures never goes out of style. Don't rush past the basics. They're the foundation everything else is built on. What JS concept took you the longest to truly "get"? Drop it in the comments 👇 #JavaScript #WebDevelopment #SoftwareEngineering #LearningInPublic #TechCareers
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🔥 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
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𝐖𝐡𝐲 𝐈 𝐚𝐜𝐭𝐮𝐚𝐥𝐥𝐲 𝐦𝐨𝐯𝐞𝐝 𝐭𝐨 𝐓𝐲𝐩𝐞𝐒𝐜𝐫𝐢𝐩𝐭 🤔 It wasn’t because it’s trending. It wasn’t because “everyone is using it.” I switched when my JavaScript projects started growing… and debugging became frustrating 😅 Simple issues turned into time-consuming problems: 🔹 unexpected undefined errors 🔹 wrong data types passed around 🔹 bugs that only showed up at runtime Everything worked… until it didn’t. That’s when TypeScript started making sense to me. With types in place: ✔ I catch mistakes earlier (before runtime) ✔ code becomes easier to understand ✔ debugging becomes way less painful It’s not about writing more code… it’s about writing more predictable code. For me: 𝐓𝐲𝐩𝐞 𝐬𝐚𝐟𝐞𝐭𝐲 = 𝐟𝐞𝐰𝐞𝐫 𝐬𝐮𝐫𝐩𝐫𝐢𝐬𝐞𝐬 🛡️ Still learning, but definitely not going back anytime soon 🚀 #TypeScript #JavaScript #WebDevelopment #FullStack #LearningInPublic #DeveloperJourney #Upskilling
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