Web Development - HTML, CSS & JavaScript
Learn to code and become a Web Developer with HTML, CSS, JavaScript , Reactjs, Wordpress, PHP, Mern & Nodejs knowledge Managed by: @love_data
Больше📈 Аналитический обзор Telegram-канала Web Development - HTML, CSS & JavaScript
Канал Web Development - HTML, CSS & JavaScript (@javascript_courses) языкового сегмента Английский является активным участником. Сейчас сообщество объединяет 55 666 подписчиков, занимая 2 378 место в категории Технологии и приложения и 6 196 место в регионе Индия.
📊 Показатели аудитории и динамика
С момента создания невідомо проект демонстрирует стремительный рост, собрав аудиторию из 55 666 подписчиков.
Согласно последним данным от 26 октября, 2026, канал показывает стабильную активность. За последние 30 дней изменение числа участников составило -4, а за последние 24 часа — -3, при этом общий охват остаётся высоким.
- Статус верификации: Не верифицирован
- Уровень вовлечённости (ER): Средний показатель вовлечённости аудитории составляет 3.66%. В первые 24 часа после публикации контент обычно набирает 1.17% реакций от общего числа подписчиков.
- Охват публикаций: В среднем каждый пост получает 2 037 просмотров. В течение первых суток публикация набирает 652 просмотров.
- Реакции и взаимодействия: Аудитория активно поддерживает контент: среднее количество реакций на один пост — 3.
- Тематические интересы: Контент сосредоточен на ключевых темах, таких как javascript, css, object, html, array.
📝 Описание и контентная политика
Автор описывает ресурс как площадку для выражения субъективного мнения:
“Learn to code and become a Web Developer with HTML, CSS, JavaScript , Reactjs, Wordpress, PHP, Mern & Nodejs knowledge
Managed by: @love_data”
Благодаря высокой частоте обновлений (последние данные получены 27 октября, 2026) канал поддерживает актуальность и высокий уровень охвата публикаций. Аналитика показывает, что аудитория активно взаимодействует с контентом, что делает его важной точкой влияния в категории Технологии и приложения.
console.log(Object.keys(person));
Output: ["name","age"]
🚀 17. Object.values()
Returns all values.
console.log(Object.values(person));
Output: ["Deepak",25]
🔥 18. Object.entries()
Returns key-value pairs. console.log(Object.entries(person));
Output: [["name","Deepak"], ["age",25]]
📦 19. Destructuring Objects
Extract values easily.
const person = { name:"Deepak", age:25 };
const { name, age } = person;
⚡ 20. Spread Operator
Copy objects.
const person = { name:"Deepak" };
const updated = {...person, city:"Pune" };
🎯 Real Interview Example
Array of Objects
const employees = [
{ id:1, name:"John" },
{ id:2, name:"Mike" }
];
console.log(employees[0].name);
Output: John
⭐ Most Important Topics For Interviews
🔥 Arrays
🔥 Objects
🔥 map()
🔥 filter()
🔥 reduce()
🔥 Destructuring
🔥 Spread Operator
🔥 Object.keys()
🔥 Object.values()
🔥 Array of Objects
📝 Mini Practice Questions
Easy:
✅ Find largest number in array,
✅ Sum all array elements,
✅ Count array length
Medium:
✅ Remove duplicates,
✅ Find second largest number,
✅ Reverse array
Advanced:
✅ Group objects by property,
✅ Custom map() method,
✅ Flatten nested arrays
Double Tap ❤️ For More
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1.59 ₽ · /balance_helpconst fruits = ["Apple", "Mango", "Banana"];
Access Elements:
console.log(fruits[0]);
Output: Apple
Important: Array indexing starts from 0.
⚡ 2. Creating Arrays
Method 1: const numbers = [10, 20, 30];
Method 2: const numbers = new Array(10, 20, 30);
🔥 3. Array Methods
push() Adds element at the end.
const arr = [1, 2];
arr.push(3);
console.log(arr);
Output: [1, 2, 3]
pop() Removes last element. arr.pop();
unshift() Adds element at beginning. arr.unshift(0);
shift() Removes first element. arr.shift();
🔄 4. Loop Through Arrays
for Loop
const nums = [1,2,3];
for(let i=0; i<nums.length; i++){
console.log(nums[i]);
}
for...of
for(let num of nums){
console.log(num);
}
🎯 5. map()
Creates a new array by transforming elements.
Example:
const nums = [1,2,3];
const doubled = nums.map(num => num * 2);
console.log(doubled);
Output: [2, 4, 6]
🔥 6. filter()
Returns elements matching condition.
Example:
const nums = [1,2,3,4,5];
const even = nums.filter(num => num % 2 === 0);
console.log(even);
Output: [2, 4]
🚀 7. reduce()
Reduces array to single value.
Example:
const nums = [1,2,3,4];
const sum = nums.reduce((total,num) => total + num, 0);
console.log(sum);
Output: 10
🧩 8. find()
Returns first matching element.
const users = [10,20,30,40];
const result = users.find(num => num > 20);
console.log(result);
Output: 30
📋 9. includes()
Checks if value exists.
const fruits = ["Apple","Mango"];
console.log(fruits.includes("Apple"));
Output: true
🔥 10. Remove Duplicates
const nums = [1,2,2,3,3];
const unique = [...new Set(nums)];
console.log(unique);
Output: [1, 2, 3]
📦 PART 2: JavaScript Objects
🧠 11. What is an Object?
An object stores data in key-value pairs.
Example:
const person = {
name: "Deepak",
age: 25,
city: "Bengalore"
};
⚡ 12. Access Object Properties
Dot Notation: console.log(person.name);
Bracket Notation: console.log(person["name"]);
🔥 13. Add New Property
person.country = "India";
console.log(person);
❌ 14. Delete Property
delete person.city;
🔄 15. Loop Through Objects
for...in
for(let key in person){
console.log(key, person[key]);
}function reverseString(str) {
return str.split('').reverse().join('');
}
4️⃣ Find the max number in an array
const max = Math.max(...arr);
5️⃣ Write a function to check if a number is prime
function isPrime(n) {
if (n < 2) return false;
for (let i = 2; i <= Math.sqrt(n); i++) {
if (n % i === 0) return false;
}
return true;
}
6️⃣ What is closure in JavaScript?
Answer:
A function that remembers variables from its outer scope even after the outer function has returned.
7️⃣ What is event delegation?
Answer:
Attaching a single event listener to a parent element to manage events on its children using event.target.
8️⃣ Difference between == and ===
Answer:
- == checks value (with type coercion)
- === checks value + type (strict comparison)
9️⃣ What is the Virtual DOM?
Answer:
A lightweight copy of the real DOM used in React. React updates the virtual DOM first and then applies only the changes to the real DOM for efficiency.
🔟 Write code to remove duplicates from an array
const uniqueArr = [...new Set(arr)];
React ❤️ for morefunction greet(name, callback) {
console.log("Hello " + name);
callback();
}
function done() {
console.log("Completed");
}
• greet("Deepak", done);
Output:
• Hello Deepak
• Completed
🚀 14. Higher Order Functions
Higher Order Functions -> functions that:
• Accept functions as arguments
• Return functions
Example:
function operation(callback) {
callback();
}
• operation(() => {
console.log("Executed");
});
⚡ 15. Closures
Closures -> one of the most important interview topics.
A closure -> allows a function to remember variables from its outer scope.
Example:
function counter() {
let count = 0;
return function() {
count++;
console.log(count);
};
}
const increment = counter();
• increment();
• increment();
Output:
• 1
• 2
🎯 16. Recursive Functions
Recursive -> a function calling itself.
Example:
function countdown(n) {
if(n === 0) {
return;
}
console.log(n);
countdown(n - 1);
}
• countdown(5);
Output:
• 5
• 4
• 3
• 2
• 1
🧮 17. Practical Example — Sum of Array
function sumArray(arr) {
return arr.reduce((sum, num) => sum + num, 0);
}
console.log(sumArray([1, 2, 3]));
Output:
• 6
⭐ Important Interview Topics
Focus heavily on:
• 🔥 Function Declaration
• 🔥 Function Expression
• 🔥 Arrow Functions
• 🔥 Scope
• 🔥 Closures
• 🔥 Callback Functions
• 🔥 Higher Order Functions
• 🔥 Recursion
• 🔥 Hoisting
📝 Mini Practice Questions
Easy
• ✅ Create calculator function
• ✅ Find maximum of two numbers
• ✅ Check even or odd
Medium
• ✅ Reverse string
• ✅ Find factorial
• ✅ Check palindrome
Advanced
• ✅ Implement debounce
• ✅ Implement throttle
• ✅ Create custom map() function
Double Tap ❤️ For More
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1.39 ₽ · /balance_helpfunction greet() {
console.log("Hello World");
}
Calling the Function:
• greet();
Output:
• Hello World
⚡ 2. Function Declaration
The most common way -> create a function.
Syntax:
function functionName() {
}
Example:
function welcome() {
console.log("Welcome to JavaScript");
}
• welcome();
🔥 3. Function Parameters
Parameters -> variables that receive values.
Example:
function greet(name) {
console.log("Hello " + name);
}
• greet("Deepak");
Output:
• Hello Deepak
🎯 4. Multiple Parameters
function add(a, b) {
console.log(a + b);
}
• add(10, 20);
Output:
• 30
🔄 5. Return Statement
return -> sends a value back from a function.
Example:
function add(a, b) {
return a + b;
}
let result = add(10, 20);
console.log(result);
Output:
• 30
🧩 6. Function Expression
A function -> stored inside a variable.
Example:
const greet = function() {
console.log("Hello");
};
• greet();
Difference:
Concept -> Function Declaration vs Function Expression
• Hoisted -> Yes vs Not Hoisted
• Defined -> separately vs Stored in variable
⚡ 7. Arrow Functions (ES6)
Modern way -> write functions.
Traditional Function:
function add(a, b) {
return a + b;
}
Arrow Function:
const add = (a, b) => {
return a + b;
};
Short Form:
const add = (a, b) => a + b;
📦 8. Default Parameters
Default values -> used when arguments are not passed.
Example:
function greet(name = "Guest") {
console.log(name);
}
• greet();
Output:
• Guest
🧠 9. Rest Parameters
Rest parameters -> collect multiple arguments into an array.
Example:
function sum(...numbers) {
console.log(numbers);
}
• sum(1, 2, 3, 4);
Output:
• [1, 2, 3, 4]
🚀 10. Scope in JavaScript
Scope -> determines where variables can be accessed.
Global Scope
let name = "Deepak";
function show() {
console.log(name);
}
• Accessible -> everywhere
Local Scope
function show() {
let age = 25;
console.log(age);
}
• Accessible -> only inside function
🔒 11. Block Scope
Variables -> declared using let and const.
if(true) {
let age = 25;
console.log(age);
}
Outside block:
console.log(age);
❌ Error
🧠 12. What is Hoisting?
Hoisting -> JavaScript moves declarations to the top before execution.
Example:
sayHello();
function sayHello() {
console.log("Hello");
}
• Works -> because function declarations are hoisted
🔥 13. Callback Functions
Callback -> function passed as an argument to another function.
Example: