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
Mostrar más📈 Análisis del canal de Telegram Web Development - HTML, CSS & JavaScript
El canal Web Development - HTML, CSS & JavaScript (@javascript_courses) en el segmento lingüístico de Inglés es un actor destacado. Actualmente la comunidad reúne a 55 722 suscriptores, ocupando la posición 2 318 en la categoría Tecnologías y Aplicaciones y el puesto 6 184 en la región India.
📊 Métricas de audiencia y dinámica
Desde su creación el невідомо, el proyecto ha mostrado un crecimiento acelerado, reuniendo a 55 722 suscriptores.
Según los últimos datos del 05 octubre, 2026, el canal mantiene una actividad estable. En los últimos 30 días la variación de miembros fue de -15, y en las últimas 24 horas de 3, conservando un alto alcance.
- Estado de verificación: No verificado
- Tasa de interacción (ER): El promedio de interacción de la audiencia es 2.60%. Durante las primeras 24 horas tras publicar, el contenido suele obtener 1.14% de reacciones respecto al total de suscriptores.
- Alcance de las publicaciones: Cada publicación recibe en promedio 1 448 visualizaciones. En el primer día suele acumular 633 visualizaciones.
- Reacciones e interacción: La audiencia responde de forma activa: el promedio de reacciones por publicación es 4.
- Intereses temáticos: El contenido se centra en temas clave como javascript, css, object, html, array.
📝 Descripción y política de contenido
El autor describe el recurso como un espacio para expresar opiniones subjetivas:
“Learn to code and become a Web Developer with HTML, CSS, JavaScript , Reactjs, Wordpress, PHP, Mern & Nodejs knowledge
Managed by: @love_data”
Gracias a la alta frecuencia de actualizaciones (últimos datos recibidos el 06 octubre, 2026), el canal mantiene la vigencia y un amplio alcance. La analítica demuestra que la audiencia interactúa activamente con el contenido, lo que lo convierte en un punto de referencia dentro de la categoría Tecnologías y Aplicaciones.
\n and \t:
const message1 = "Hello\nWorld";
console.log(message1);
// Hello
// World
const message2 = "Name:\tRahul";
console.log(message2); // Name: Rahul (with tab)
🔹 Comparing Strings
2️⃣6️⃣ String Comparison
Strings can be compared:
console.log("apple" === "apple"); // true
console.log("Apple" === "apple"); // false - case-sensitive
const input = "ADMIN";
if (input.toLowerCase() === "admin") {
console.log("Access granted");
}
⭐ Practical String Processing
Imagine a user enters an email:
const input = " USER@GMAIL.COM ";
const email = input.trim().toLowerCase();
console.log(email); // user@gmail.com
if (email.includes("@")) {
console.log("Email looks valid");
}
This combines:
• trim() ↓ toLowerCase() ↓ includes()
🧠 Real-World Example
Suppose you receive this data:
const data = "Amit, Priya, Rahul, Neha";
const names = data.split(",");
const cleanedNames = names.map(name => name.trim());
console.log(cleanedNames); // ["Amit", "Priya", "Rahul", "Neha"]
const filteredNames = cleanedNames.filter(
name => name.startsWith("R")
);
console.log(filteredNames); // ["Rahul"]
⚠️ Common Beginner Mistakes
• Mistake 1: Forgetting that strings are zero-indexed
const word = "Hello";
console.log(word[0]); // H not e
• Mistake 2: Expecting string methods to modify the original string
const name = "rahul";
name.toUpperCase();
console.log(name); // still "rahul"
const upperName = name.toUpperCase(); // correct
•
Mistake 3: Forgetting trim()
• User input often has accidental spaces: " Rahul "
•
Mistake 4: Confusing split() and join()
• split() → string → array
• join() → array → string
💻 Practice
•
1️⃣ Reverse a String: Given const word = "JavaScript"; Try to produce tpircSavaJ. Hint: split() + reverse() + join()
•
2️⃣ Count Characters: Count characters in "JavaScript"
•
3️⃣ Convert to Uppercase: Convert "javascript is powerful" to uppercase.
•
4️⃣ Extract Text: From "JavaScript" extract Script
•
5️⃣ Replace Text: Convert "I love Python" into "I love JavaScript"
•
6️⃣ Clean User Input: Given const input = " HELLO JAVASCRIPT "; Produce hello javascript
•
7️⃣ Challenge: Given const email = " USER@EXAMPLE.COM ";
Create a cleaned version that:
- Removes extra spaces
- Converts everything to lowercase
- Checks whether it contains @
- Prints "Valid email format" if it does.
🧠 Double Tap ❤️ For More
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1.44 ₽ · /balance_helpconst fileName = "report.pdf";
console.log(fileName.endsWith(".pdf")); // true
🔹 Finding Positions
1️⃣3️⃣ indexOf()
Returns the position of the first occurrence.
const message = "Hello JavaScript";
console.log(message.indexOf("JavaScript")); // 6
console.log(message.indexOf("Python")); // -1 - not found
1️⃣4️⃣ lastIndexOf()
Returns the position of the last occurrence.
const text = "JavaScript is powerful. JavaScript is popular.";
console.log(text.lastIndexOf("JavaScript")); // 25
🔹 Extracting Parts of a String
1️⃣5️⃣ slice()
slice() extracts part of a string.
const language = "JavaScript";
console.log(language.slice(0, 4)); // Java
The ending index is not included.
• 0 → J
• 1 → a
• 2 → v
• 3 → a
• 4 → S
• So slice(0, 4) returns characters from index 0 through 3.
1️⃣6️⃣ Negative Indexes
You can use negative indexes with slice().
const language = "JavaScript";
console.log(language.slice(-6)); // Script
🔹 substring()
1️⃣7️⃣ substring()
substring() can also extract part of a string.
const language = "JavaScript";
console.log(language.substring(0, 4)); // Java
For modern JavaScript code, slice() is often more convenient because it supports negative indexes.
🔹 Replacing Text
1️⃣8️⃣ replace()
Replaces the first matching occurrence.
const message = "I like JavaScript";
const updated = message.replace("JavaScript", "Python");
console.log(updated); // I like Python
1️⃣9️⃣ replaceAll()
Replaces all matching occurrences.
const message = "JavaScript is great. JavaScript is popular.";
const updated = message.replaceAll("JavaScript", "JS");
console.log(updated); // JS is great. JS is popular.
🔹 Splitting Strings
2️⃣0️⃣ split()
split() converts a string into an array.
const names = "Amit,Priya,Rahul";
const result = names.split(",");
console.log(result); // ["Amit", "Priya", "Rahul"]
const sentence = "Learn JavaScript step by step";
const words = sentence.split(" ");
console.log(words); // ["Learn", "JavaScript", "step", "by", "step"]
🔹 Joining Data
2️⃣1️⃣ join()
join() combines array elements into a string.
const words = ["Learn", "JavaScript"];
const sentence = words.join(" ");
console.log(sentence); // Learn JavaScript
Notice:
• split() → string → array
• join() → array → string
⭐ Template Literals
2️⃣2️⃣ What Are Template Literals?
Template literals use backticks:
const message = `Hello`;
Their biggest advantage is easy string interpolation.
const name = "Rahul";
const age = 25;
const message = `My name is ${name} and I am ${age} years old.`;
console.log(message); // My name is Rahul and I am 25 years old.
2️⃣3️⃣ Expressions Inside Template Literals
You can also use expressions.
const price = 1000;
const quantity = 3;
const total = `Total: ${price * quantity}`;
console.log(total); // Total: 3000
2️⃣4️⃣ Multi-line Strings
Template literals make multi-line text easier.
const message = `
Hello Rahul,
Welcome to JavaScript.
Keep learning!
`;
console.log(message);const name = "Rahul";
const city = "Pune";
const message = "Welcome to JavaScript";
Strings are used everywhere:
• User names
• Emails
• Search queries
• API responses
• Messages
• URLs
• Form inputs
• File names
Understanding string manipulation is therefore essential.
1️⃣ Creating Strings
JavaScript provides three common ways to create strings.
• Double quotes:
const name = "Rahul";
• Single quotes:
const name = 'Rahul';
• Template literals:
const name = `Rahul`;
Template literals use backticks.
They become especially useful when inserting variables into strings.
2️⃣ String Length
Use .length to find the number of characters.
const message = "JavaScript";
console.log(message.length); // 10
Spaces are also counted.
const message = "Hello World";
console.log(message.length); // 11 - space is included
3️⃣ Accessing Characters
Strings use zero-based indexing, just like arrays.
const language = "JavaScript";
console.log(language[0]); // J
console.log(language[4]); // S
console.log(language[language.length - 1]); // t - last character
4️⃣ Strings Are Immutable
Strings cannot be changed directly.
const name = "Rahul";
name[0] = "K"; // Does NOT work
Instead, you create a new string:
const name = "Rahul";
const updatedName = "K" + name.slice(1);
console.log(updatedName); // Kahul
This concept of immutability is important when working with strings.
🔹 Changing Letter Case
5️⃣ toUpperCase()
Converts a string to uppercase.
const name = "rahul";
console.log(name.toUpperCase()); // RAHUL
6️⃣ toLowerCase()
Converts a string to lowercase.
const name = "RAHUL";
console.log(name.toLowerCase()); // rahul
A common real-world use:
const userInput = "ADMIN";
if (userInput.toLowerCase() === "admin") {
console.log("Admin user");
}
🔹 Removing Unwanted Spaces
7️⃣ trim()
trim() removes whitespace from the beginning and end of a string.
const name = " Rahul ";
console.log(name.trim()); // Rahul
This is extremely useful when processing form inputs.
8️⃣ trimStart()
Removes whitespace from the beginning.
const text = " Hello";
console.log(text.trimStart()); // "Hello"
9️⃣ trimEnd()
Removes whitespace from the end.
const text = "Hello ";
console.log(text.trimEnd()); // "Hello"
🔹 Searching Strings
🔟 includes()
Checks whether a string contains specific text.
const message = "Welcome to JavaScript";
console.log(message.includes("JavaScript")); // true
const email = "user@gmail.com";
console.log(email.includes("@")); // true
1️⃣1️⃣ startsWith()
Checks whether a string starts with specific text.
const url = "https://example.com";
console.log(url.startsWith("https")); // true
1️⃣2️⃣ endsWith()
Checks whether a string ends with specific text.function add(a, b) {
return a + b;
}
Every time: add(2, 3) returns: 5. A function that depends on changing external state can behave differently. Understanding pure functions becomes particularly useful when working with modern frontend frameworks.
🧠 Real-World Example
Imagine an online shopping application.
function calculateDiscount(price, discount) {
return price - discount;
}
function calculateTax(price, taxRate) {
return price * taxRate;
}
let price = 2000;
let discountedPrice = calculateDiscount(price, 300);
let tax = calculateTax(discountedPrice, 0.18);
console.log(discountedPrice);
console.log(tax);
Instead of putting everything into one huge block of code, each function handles a specific responsibility.
🧠 Double Tap ❤️ For More
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2.84 ₽ · /balance_help