Closures in JavaScript Explained

🚀 Day 17/30 – slice() vs splice() in JavaScript These two methods look similar but behave very differently 👇 🔹 slice() Returns a new array Does NOT modify original array Used to extract elements 🔹 splice() Modifies the original array Can add/remove elements Used for updating the array 💡 In simple terms: 👉 slice = copy 👉 splice = change learn with w3schools.com #Day17 #FrontendDeveloper #JavaScript #InterviewPreparation #WebDevelopment #30DaysChallenge JavaScript Mastery

🚀 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 3/100 of JavaScript 🚀 Today’s Topic: "use strict" "use strict" enables strict mode in JavaScript, which makes the code run in a more controlled and error-prone way by enforcing stricter rules - Variables must be declared before use - Using undeclared variables throws a ReferenceError - Duplicate parameter names are not allowed - this in functions (non-methods) is undefined instead of the global object. It helps catch common mistakes early and prevents unsafe actions in the code Strict mode can be applied to: - Entire script - Specific functions Using strict mode improves code quality, predictability, and makes debugging easier #Day3 #JavaScript #100DaysOfCode

Day 2/100 of JavaScript 🚀 Today’s Topic: "let", "const", "var", hoisting and TDZ. "var", "let", and "const" are used to declare variables, but they differ in scope and initialization behavior - "var" is function-scoped and during the creation phase it gets initialized with "undefined", so it can be accessed before assignment. - "let" and "const" are block-scoped and are registered in memory during creation, but not initialized immediately. This leads to TDZ (Temporal Dead Zone) a phase where the variable exists in memory but remains uninitialized and cannot be accessed. Accessing "let" or "const" variables before initialization results in a ReferenceError. - "const" must be initialized at declaration and cannot be reassigned. - "let" allows reassignment but not redeclaration in the same scope. These differences make "let" and "const" more predictable and safer compared to "var". #Day2 #JavaScript #100DaysOfCode

💡 Pure vs Impure Functions in JavaScript 🔹 Pure Function Same input → Same output. No side effects. const add = (a, b) => a + b; 🔸 Impure Function Depends on or changes external state. let total = 0; const addToTotal = (v) => total += v; 🚀 Why it matters? Predictable code. Easier testing. Fewer bugs. 👉 Write pure functions whenever possible. #JavaScript #CleanCode #FunctionalProgramming

🚀 Day 1/30 – JavaScript Challenge LeetCode 2667 – Create Hello World Function 🧩 Problem: Write a function that returns a new function. That new function should always return "Hello World", no matter what arguments are passed. 🧠 Explanation: createHelloWorld() returns another function. The returned function uses (...args) to accept any number of arguments. But we ignore all inputs and always return "Hello World". 💡 Key Concept: This problem is based on: Higher Order Functions (function returning function). Rest Parameters (...args). Function independence from input. #javascript #30Days #Leetcode

Day 9/30 Functions, Parameters, and Return Values in JavaScript Functions in JavaScript are reusable blocks of code designed to perform specific tasks. They help improve organization, reduce repetition, and make programs easier to maintain. A function can receive Parameters, which act like placeholders for values that are passed in when the function is called. These parameters allow the function to work with dynamic input. After processing the input, a function can provide an output using the return statement. The returned value can then be stored, displayed, or used in further calculations. Together, functions, parameters, and return values make JavaScript logic flexible, reusable, and efficient. #M4ACELearningChallenge #QualityAssurance #AutomationTesting #JavaScript #LearningInPublic

A quick async themed JavaScript bug hunt. We log a few values, schedule a setTimeout with zero delay, and resolve a Promise. Nothing looks unusual, but the output order might be unexpected. What order do the four strings print in, and why? Check it out and share your answer in the comments.

The WTF JS GitHub repository is a hilarious yet insightful collection of JavaScript quirks and WTF moments. Learn and laugh while uncovering the language's weird side! 🔥 Link 🔗: https://lnkd.in/dWYWQmfB I hope this helps ✅ Do Like 👍 & Repost 🔄 #html #css #javascript #typescript #react #viral

One thing that used to confuse me in JavaScript: Why do both == and === even exist? Coming from other languages, it felt unnecessary. Turns out, they solve two different problems. == tries to be flexible and converts values: 0 == "0" → true === is strict, no conversion: 0 === "0" → false So it’s not random. It’s just two different rules: flexible vs exact. Most of the time, you just want exact. #javascript #webdevelopment