Discovering JavaScript Symbols in 100 Days of Code

🚀 Day 39/50 – Scope in JavaScript Today I learned about Scope in JavaScript, which defines where variables can be accessed in a program. 🔹 Scope determines the visibility and accessibility of variables. 📌 Types of Scope in JavaScript 1️⃣ Global Scope – Variables declared outside any function can be accessed anywhere. let name = "Priyanka"; function show() { console.log(name); } show(); 2️⃣ Function Scope – Variables declared inside a function are accessible only within that function. function test() { let msg = "Hello"; console.log(msg); } test(); 3️⃣ Block Scope – Variables declared with let and const inside {} are block-scoped. if(true){ let x = 10; console.log(x); } 4️⃣ Local Scope – Variables declared inside a block or function are local to that area. 💡 Key Learnings: ✅ var → function scoped ✅ let and const → block scoped ✅ Scope helps avoid variable conflicts ✅ Improves code security and readability Thanks for mentors 10000 Coders Raviteja T Abdul Rahman #Day39 #50DaysOfCode #JavaScript #WebDevelopment #FrontendDeveloper #CodingJourney #LearningEveryday

🚀 Arrays are NOT real arrays in JavaScript. That was one of the most interesting things I learned today while studying Arrays in JavaScript. At first, arrays seem simple — just a collection of elements. But under the hood, JavaScript arrays are actually objects with special behavior, not fixed-size contiguous memory structures like in languages such as C++. What I learned about Arrays: • Arrays in JavaScript are mutable • They can store multiple data types • They are dynamic in size Key operations I practiced: • Adding/removing elements → push(), pop(), shift(), unshift() • Looping → classic for loop and modern iteration methods • Searching → indexOf(), lastIndexOf(), includes() • Manipulation → slice(), splice() • Conversion → join() (array → string) • Spread operator → modern and powerful way to copy/merge arrays One important insight: The sort() method can behave unexpectedly with numbers because it sorts values as strings by default. Example: [10, 2, 5].sort() // Output -> [10, 2, 5] To sort numbers correctly, we need a comparison function. To summarize everything, I created a detailed carousel Notes (Notes given by Rohit Negi). Course Instructor: Rohit Negi | Youtube Channel: Coder Army #JavaScript #WebDevelopment #LearningJourney #BuildInPublic #FrontendDevelopment #Fullstackdevelopment #Coding

🚀 What I Learned Today – JavaScript Arrays Today I explored Arrays in JavaScript and here are the key takeaways 👇 🔹 Arrays are a collection of items 🔹 They are linear (elements stored sequentially) 🔹 Arrays are mutable (can be changed after creation) 📌 Array Indices Positions of elements in an array (starting from 0) 📌 Looping Through Arrays Used to print or access all elements easily 📌 Useful Array Methods ✔️ push() – add element to end ✔️ pop() – remove element from end ✔️ unshift() – add element to start ✔️ shift() – remove element from start ✔️ toString() – convert array to string ✔️ concat() – merge arrays ✔️ slice() – get part of array (no change to original) ✔️ splice() – modify array (add/remove/replace) 💡 Example: slice(start, end) splice(start, deleteCount, newElement) Learning step by step and building strong fundamentals 💪 #JavaScript #WebDevelopment #CodingJourney #FrontendDevelopment #100DaysOfCode)

Day 1 of 30 days of javascript challenge. problem-2667 Problem - Write a function createHelloWorld that returns another function, that returns "Hello World" As this is my first code, I revised my notes on javascript scope. ☑️ Function scope - Any variables declared inside a function body cannot be accessed outside the function body, but global variables can be used inside function body ☑️ Block scope - Any variable declared inside { } cannot be used outside the { } block, although it supports only let and const keyword, var can be used ☑️ Lexical scope - A variable declared outside a function can be accessed inside another function defined after the variable declaration. (The opposite is not true ) This problem uses the concept of closures and higher order functions. Please feel free to discuss where can I improve the code or if you have a different perspective, comment below your views. #javascript #coding #development #motivation #goals #leetcode #webdevelopment

Day 2 of My JavaScript Journey 🚀 Today, I learned about values and variables in JavaScript. Values are the most fundamental unit of information in programming. Everything in JavaScript is built around values; numbers, text, true/false, etc. Variables, on the other hand, are like containers (or boxes) used to store these values so they can be reused later in a program. For example: let age = 20; Here, "20" is the value, and "age" is the variable storing it. One simple way to understand it: Values = the data Variables = where the data is stored Key takeaway: Variables make it easier to manage and reuse data efficiently in your code. I’m documenting my journey daily as I grow in JavaScript. #JavaScript #WebDevelopment #LearningInPublic #100DaysOfCode

🚀 Day 7/100 of #100DaysOfCode Today was all about strengthening JavaScript fundamentals — revisiting concepts that seem simple but are often misunderstood. 🔁 map() vs forEach() Both are used to iterate over arrays, but they serve different purposes: 👉 map() Returns a new array Used when you want to transform data Does not modify the original array Example: const doubled = arr.map(num => num * 2); 👉 forEach() Does not return anything (undefined) Used for executing side effects (logging, updating values, etc.) Often modifies existing data or performs actions Example: arr.forEach(num => console.log(num)); ⚔️ Key Difference: Use map() when you need a new transformed array Use forEach() when you just want to loop and perform actions ⚖️ == vs === (Equality in JS) 👉 == (Loose Equality) Compares values after type conversion Can lead to unexpected results Example: '5' == 5 // true 😬 👉 === (Strict Equality) Compares value AND type No type coercion → safer and predictable Example: '5' === 5 // false ✅ 💡 Takeaway: Small concepts like these make a big difference in writing clean, bug-free code. Mastering the basics is what separates good developers from great ones. 🔥 Consistency > Intensity On to Day 8! #JavaScript #WebDevelopment #CodingJourney #LearnInPublic #Developers #100DaysOfCode #SheryiansCodingSchool #Sheryians

Day 4 of 30 Days of JavaScript💻....#JavaScript30 Today’s focus was on working with some of the most powerful and commonly used JavaScript array methods: 1 . filter() Used to extract specific data from arrays based on conditions. 2 . map() Learned how to transform array data into a new format. 3 . sort() Sorted complex datasets like objects and strings alphabetically and numerically. 4 . reduce() Takes an array and reduces it into one final result. Through these exercises, I understood how JavaScript can process datasets efficiently using clean and readable functional-style code. Working through these concepts step by step is helping me strengthen my logic and gain more confidence in writing JavaScript, which will definitely support me in frontend development and problem solving. #JavaScript #WebDevelopment #LearningInPublic #CodingJourney #FrontendDevelopment #30DaysOfCode

🚀 Just solved the "Best Time to Buy and Sell Stock" problem in JavaScript! Today I worked on improving my problem-solving skills by implementing a solution to calculate the maximum profit from stock prices. 🔍 Problem: Given an array of prices, determine the maximum profit you can achieve by buying and selling once. 💡 Approach: I started with a brute-force solution using nested loops to compare every possible buy/sell pair. While not the most optimal (O(n²)), it helped me deeply understand the problem before optimizing. 📌 Example: Input: [10, 1, 5, 6, 7, 1] Output: 6 🧠 Key takeaway: Sometimes starting simple is the best way to build strong intuition before moving to more efficient solutions. 👉 Check out my code and more JavaScript patterns here: https://lnkd.in/ej4fNeZs #JavaScript #Coding #ProblemSolving #100DaysOfCode #WebDevelopment #LearningInPublic

Day 4 of my JavaScript learning journey. Today I learned one of the most confusing concepts so far: Hoisting. I tried something strange. greet(); function greet() { console.log("Hello!"); } The function worked even before it was defined. That’s because of hoisting. JavaScript reads the whole code first and moves function declarations to the top internally. But variables behave differently. console.log(x); var x = 5; This prints undefined, not 5. And if we use let or const, JavaScript throws a ReferenceError. This area is called the Temporal Dead Zone. My takeaway today: Always declare variables before using them. Day 4 done. JavaScript keeps getting more interesting. What JavaScript concept confused you the most when you first learned it? #JavaScript #LearningInPublic #WebDevelopment #100DaysOfCode #Frontend

Another Day of My JavaScript Mastering Learning Journey DEY WITH ME!!! Today I explored one of the most important concepts in JavaScript: Prototypes. In JavaScript, objects can share properties and methods through something called a prototype. Instead of every object having its own copy of a method, JavaScript stores shared methods on the prototype so multiple objects can reuse them. For example, if we create a constructor like Person, we can add methods to Person.prototype. Every object created from Person will automatically have access to those methods. This approach helps save memory and keep code more efficient, because the methods are shared rather than duplicated for every object. Example idea: Create a constructor (like Person) Add methods to Person.prototype Every instance can use those methods Understanding prototypes helped me see how JavaScript handles inheritance and object behavior under the hood. Small steps like this are helping me build a stronger foundation as I continue learning JavaScript and backend development. #JavaScript #WebDevelopment #CodingJourney #LearningInPublic