JavaScript Essentials 🌟

Welcome to the JavaScript essentials guide! This document covers core concepts every developer should know. Let's dive in!

🐶 Variables & Data Types

JavaScript uses let, const, and var for variable declaration.

• let allows reassignment
• const is for constants
• var is function-scoped (older style)

Common data types include:

• Primitive: Number, String, Boolean, Null, Undefined, Symbol, BigInt
• Object: Arrays, Dates, RegEx, etc.

💡 Tip: Always use const unless you need to mutate the variable!

🧩 Functions

Functions are reusable blocks of code.

function greet(name) {
  return `Hello, ${name}!`;
}
console.log(greet("World")); // Output: Hello, World!

Arrow functions (ES6+):

const greet = (name) => `Hi, ${name}!`;

🎮 Control Structures

Use if/else, switch, for, while, and do/while for logic flow.
Example:

for (let i = 0; i < 5; i++) {
  console.log(i);
}

🏗️ Objects & Arrays

Objects store key-value pairs:

const person = { name: "Alice", age: 30 };

Arrays hold ordered collections:

const fruits = ["apple", "banana", "cherry"];

⚡ Asynchronous Programming

JavaScript handles async operations with:

• async/await
• Promise objects
• setTimeout/setInterval

Async function example:

async function fetchData() {
  const response = await fetch("https://api.example.com/data");
  return response.json();
}

For deeper exploration, check our JavaScript Basics guide.

📚 Resources

• JavaScript Syntax
• ES6 Features Overview
• Debugging Techniques