Implementing custom reduce() function on LeetCode

Day 6 of #30DaysOfJavaScript on LeetCode Today's challenge: 2634 — Filter Elements from Array The task was to implement a custom filter function that returns a new array containing only the elements that satisfy a given condition — similar to the built-in Array.filter() method, but without using it. Here’s my solution 👇 var filter = function(arr, fn) { let ans = []; for (let i = 0; i < arr.length; i++) { if (fn(arr[i], i)) ans.push(arr[i]); } return ans; }; This challenge was a great way to understand how callback functions and conditional logic work together in JavaScript — it really helps appreciate how built-in methods like filter() operate under the hood! If you’d like to try it out, check it here: https://lnkd.in/g6WC5mu7 #JavaScript #LeetCode #CodingChallenge #LearningJourney #30DaysOfCode #Functions #Callbacks #Arrays #Programming #Filter

Every JavaScript developer has hit that confusing moment when var starts acting like it has a mind of its own 😅 I still remember spending hours debugging a scope issue… only to find out that var is function-scoped, while let and const are block-scoped. That’s exactly what we break down in our new Instagram video a quick visual guide to mastering var, let, and const, so you’ll never get caught off guard again. 📹 Check out the full video on our Instagram-> link in the comments 👇 #JavaScript #WebDevelopment #CodingTips #LearnToCode #FrontendDevelopment #Programming #TechEducation

Day 9 of #30DaysOfJavaScript on LeetCode Today's challenge: 2703 — Return Length of Arguments Passed The task was to write a function that returns the number of arguments passed to it — a simple yet elegant problem to explore rest parameters in JavaScript. Here’s my solution 👇 var argumentsLength = function(...args) { return args.length; }; It’s a short problem but a great reminder that even small concepts like this are essential for mastering function flexibility in JavaScript! Try it out here : https://lnkd.in/g6WC5mu7 #JavaScript #LeetCode #CodingChallenge #LearningJourney #30DaysOfCode #Functions #RestParameters #Programming

Day 15 of #30DaysOfJavaScript on LeetCode Today's Challenge: 2725 — Interval Cancellation This problem focused on mastering repeated asynchronous execution in JavaScript — specifically, how to repeatedly run a function using setInterval() and stop it with clearInterval(). Here’s my solution 👇 var cancellable = function(fn, args, t) { fn(...args); let timer = setInterval(() => fn(...args), t); let cancelFn = () => clearInterval(timer); return cancelFn; }; This exercise helped me understand how interval-based scheduling works and how to control execution flow by canceling ongoing intervals a common pattern in real-world applications like periodic data fetching or live updates. Try it out here: https://lnkd.in/g6WC5mu7 #JavaScript #LeetCode #CodingChallenge #AsyncAwait #Promises #30DaysOfCode #Programming #Developers #LearningJourney

🚀 Day 81 of #100DaysOfCode Today I learned how to create object literals in JavaScript. An object literal lets you store related data as key-value pairs inside curly braces. For example: const car = { brand: "Toyota", year: 2020, color: "red" }; This way, you can easily organize, access, and update complex data as one unit. Object literals are foundational for structuring real-world information in your programs. #JavaScript #ObjectLiterals #Programming #100DaysOfCode

Day 8 of #30DaysOfJavaScript on LeetCode Today's challenge: 2629 — Function Composition The task was to implement a function that takes an array of functions [f1, f2, f3, ..., fn] and returns a new function that represents their composition. In simple terms, the composed function should apply all the given functions from right to left, just like: f(g(h(x))) Here’s my solution 👇 var compose = function(functions) { return function(x) { let res = x; for (let i = functions.length - 1; i >= 0; i--) { res = functions[i](res); } return res; } }; This challenge gave me a deeper understanding of how function chaining and composition work in JavaScript — building complex logic from smaller, reusable functions. It’s a beautiful example of how functional programming principles simplify problem-solving! Try it out here : https://lnkd.in/g6WC5mu7 #JavaScript #LeetCode #CodingChallenge #LearningJourney #30DaysOfCode #Functions #Callbacks #Programming #Composition

🚀 JavaScript Closures — A Little Magic Trick! Imagine… a function that can remember its past values, even after it has finished running! 😲 That’s the magic of closures. In this 3-frame short video, you’ll see: ✨ What a closure is ✨ How an inner function can access outer variables ✨ Why we use closures #JavaScript #CodingMagic #WebDev #Closures #TechFun #Programming #DeveloperLife

If you are still struggling to understand some JavaScript trick concept of Deep and Shallow clone join me as I explore and break down how to deep and shallow clone and also how to apply them with confidence Let's discuss Deep and Shallow Clone in JavaScript jabo Landry ・ Nov 1 #webdev #javascript #programming #beginners https://lnkd.in/gYeFwW4e

If you are still struggling to understand some JavaScript trick concept of Deep and Shallow clone join me as I explore and break down how to deep and shallow clone and also how to apply them with confidence Let's discuss Deep and Shallow Clone in JavaScript jabo Landry ・ Nov 1 #webdev #javascript #programming #beginners https://lnkd.in/gYeFwW4e