"Memoize function in JavaScript for performance optimization"

🚀 Day 4 of My 30 Days of JavaScript Journey ✅ Challenge: Create Counter Object (LeetCode #2665) Write a function createCounter(init) that returns an object with three functions: increment() → increases the value by 1 and returns it. decrement() → decreases the value by 1 and returns it. reset() → resets the value to the initial value and returns it. 💻 Language Used: JavaScript ❓ Problem Link: https://lnkd.in/gKxPxb8Y 💡 Solution: https://lnkd.in/g3jv6Nfi 🧠 Concept Highlighted: This challenge strengthens understanding of closures and object methods in JavaScript. It shows how functions can preserve and modify internal state — a key concept in building dynamic, stateful applications. #JavaScript #LeetCode #30DaysOfCode #CodingChallenge #WebDevelopment #FrontendDevelopment #LearningEveryday #Closures #ProblemSolving

🚀 Day 5 of My 30 Days of JavaScript Challenge 🧩 Problem: Apply Transform Over Each Element in Array (LeetCode #2635) Given an integer array arr and a mapping function fn, return a new array such that: newArray[i] = fn(arr[i], i) Solve this without using the built-in Array.map() method. 💻 Language: JavaScript ❓ Question: https://lnkd.in/eq8qYfpb 💡 Solution: https://lnkd.in/eT5U2kBp 🧠 Concepts Used: Higher-order functions (passing functions as arguments) Loops and callback functions Core idea behind how .map() works internally 📚 Takeaway: By recreating the Array.map() method manually, I learned how callback execution and array transformations work under the hood — a must-know for mastering JavaScript fundamentals. #Day5 #JavaScript #30DaysOfCode #LeetCode #CodingChallenge #WebDevelopment #FrontendDevelopment #100DaysOfCode

🚀 Day 4 of My 30 Days of JavaScript Challenge 🧩 Problem: Create Counter II (LeetCode #2665) Write a function createCounter(init) that returns an object with three functions: increment() → increases the current value by 1 and returns it decrement() → decreases the current value by 1 and returns it reset() → resets the value back to init and returns it 💻 Language: JavaScript ❓ Question: https://lnkd.in/eupkr-a3 💡 Solution: https://lnkd.in/eq3BEsn2 🧠 Concepts Used: Closures for maintaining private state across function calls Object methods to encapsulate multiple related actions State management inside functions 📚 Takeaway: This challenge reinforces closures and encapsulation — two powerful ideas that make JavaScript functions behave like real objects with memory and behavior. #Day4 #JavaScript #30DaysOfCode #LeetCode #CodingChallenge #WebDevelopment #FrontendDevelopment #100DaysOfCode

🚀 Day 10 of My 30 Days of JavaScript Challenge 🧩 Problem: Allow One Function Call (LeetCode #2666) Given a function fn, return a new function that ensures fn can only be called once. The first call returns the actual result, and every subsequent call returns undefined. 💻 Language: JavaScript 📖 Problem Link: https://lnkd.in/epnrfahZ 💡 Solution: https://lnkd.in/eGQKWkEk 🧠 Concepts Used Closures to store state (whether function is already called) Function Wrapping Higher-Order Functions 📚 Takeaway This problem is a great example of how closures preserve state between function calls — an essential concept for: Memoization API rate-limiting Event listener control #Day10 #JavaScript #30DaysOfCode #LeetCode #WebDevelopment #CodingChallenge #Closures #FrontendDevelopment #100DaysOfCode

🚀 Day 3 of My 30 Days of JavaScript Challenge 🧩 Problem: Implement expect() Function (LeetCode #2704) Write a function expect that helps developers test their code. It takes a value val and returns an object with two methods: toBe(val) → returns true if both values are strictly equal (===), else throws "Not Equal" notToBe(val) → returns true if both values are not strictly equal (!==), else throws "Equal" 💻 Language: JavaScript ❓ Question: https://lnkd.in/eJcRKeme 💡 Solution: https://lnkd.in/eZY9mYHN 🧠 Concepts Used: Higher-order functions (function returning object with functions) Error handling using throw new Error() Strict equality (===) in JavaScript 📚 Takeaway: This exercise reinforces function design, object methods, and error handling — the foundation for building custom testing utilities and debugging tools in JavaScript. #Day3 #JavaScript #LeetCode #30DaysOfCode #CodingChallenge #WebDevelopment #FrontendDevelopment #100DaysOfCode

Day 8 of #30DaysOfJavaScript: Counting Function Arguments with Rest Parameters! 🎯 Solved an interesting and fundamental problem today—writing a function that returns the count of arguments passed to it. This challenge sharpened my understanding of JavaScript’s rest parameters and how they simplify working with variable numbers of arguments. Here’s my solution: javascript var argumentsLength = function(...args) { return args.length; }; Key insights gained: rest parameters allow capturing an indefinite number of arguments in an array-like structure. This approach is cleaner and more intuitive than using the legacy arguments object. Mastering these basics is essential for writing flexible, reusable functions in JavaScript. Excited to keep progressing on this learning journey and uncovering more of JavaScript’s powerful features every day! If you’re also working through JavaScript fundamentals or coding challenges, let’s connect and share tips. #JavaScript #RestParameters #CodingChallenge #LeetCode #WebDev #LearningByDoing #SoftwareDevelopment

Day 5 of #30DaysOfJavaScript: Creating My Own Filter Function from Scratch! 🎯 Today, I tackled a great exercise that challenged me to build a custom filter function without using JavaScript’s built-in .filter() method. This involved iterating over an array and using a callback function to decide which elements to keep based on truthy values. Here’s a peek at the solution I wrote: Key takeaways from this challenge: Deepened my understanding of higher-order functions and callback usage. Learned how to evaluate truthy and false values in JavaScript more effectively. Gained appreciation for the power and convenience of built-in array methods by implementing one manually. This hands-on approach is helping me grasp fundamental JavaScript concepts in detail while preparing for real-world coding challenges. Excited to keep growing and solving more problems along the way! Let’s connect and share knowledge. #JavaScript #CodingChallenge #WebDevelopment #LeetCode #ArrayMethods #LearningByBuilding #DeveloperJourney

💡 Understanding Object Methods in JavaScript Working with objects is fundamental in JS. Here's a quick overview of some powerful methods: Object.keys(obj) → Returns all keys of the object. Object.values(obj) → Returns all values of the object. Object.entries(obj) → Returns key-value pairs as arrays. obj.hasOwnProperty("property") → Checks if the object has a specific property. Object.assign({}, obj, { newProperty: "newValue" }) → Creates a new object by merging existing ones. 👉 View the full example on GitHub: https://lnkd.in/dDN-vDkD #JavaScript #FullStack #100xDevs #WebDevelopment #Coding #JSConcepts #LearnJavaScript

🚀 Day 19 of 30 Days of JavaScript – LeetCode Problem: 1207. Unique Number of Occurrences Today’s challenge was all about checking whether the number of occurrences of each value in an array is unique. ✅ My Approach 1️⃣ Count occurrences I used a for...of loop to count how many times each element appears in the array. 2️⃣ Store frequency results This gives me an object holding the occurrence count of every unique item. 3️⃣ Convert to a Set I extracted the values and converted them into a Set using new Set(), since a set automatically removes duplicates. 4️⃣ Compare values Arrays and sets can’t be directly compared, so I converted both to strings using JSON.stringify() to compare their datatype + values. 5️⃣ Return result If both match, I return true; otherwise, false. #JavaScript #LeetCode #30DaysOfCode #codingjourney #developerlife

The JavaScript Event Loop — The Hidden Multitasking Hero If JavaScript is single-threaded, how does it look like it’s doing so many things at once? 🤔 Meet the Event Loop — the patient snake 🐍 that makes everything flow smoothly. 🧩 In simple words: JS runs one thing at a time (main thread). When async tasks finish, the Event Loop decides when to bring them back into action — like a patient teacher calling students one by one from different queues 😄 ✨ Takeaway: --> Promises (microtasks) always run before setTimeout (macrotasks). --> JS isn’t truly “multi-threaded” — it’s just a great illusionist. 🎩 Next up → 🧠 “this” Keyword — The Most Confused Owl in JavaScript 🦉 #JavaScript #EventLoop #AsyncJS #WebDevelopment #FrontendDevelopment #CodingCommunity #100DaysOfCode #LearnToCode #MERNStack #ProgrammingHumor