🔥 JavaScript Functions - Interactive Lesson

Functions are reusable blocks of code you can call whenever you want. They help keep your code organized, clean, and DRY (Don't Repeat Yourself).

📚 Example 1: Basic Function Declaration

// Declare a function
function greet(name) {
  return "Hello, " + name + "!";
}

// Call the function and log output
const message = greet("Alex");
console.log(message);

Output will appear here...

📂 Example 2: Arrow Functions

// Arrow function syntax
const add = (a, b) => a + b;

console.log("3 + 4 =", add(3, 4));

Output will appear here...

🧰 Example 3: Function with Default Parameters

// Default parameter example
function multiply(a, b = 2) {
  return a * b;
}

console.log(multiply(5));      // 10 (b defaults to 2)
console.log(multiply(5, 3));   // 15 (b overridden)

Output will appear here...

⚡ Quick Tips

Functions can be declared with function keyword or as arrow functions (=>).
Parameters can have default values.
Functions help you avoid repeating code.
Use return to output values from a function.