# Traditional function
function add(a, b) { return a + b; }

# Arrow function
const add = (a, b) => a + b; # implicit return
const square = x => x * x; # single param
const greet = () => "Hello"; # no params

# Array destructuring
const [a, b] = [1, 2]; # a=1, b=2
const [x, , z] = [1, 2, 3]; # skip middle

# Object destructuring
const {name, age} = user; # extract properties
const {name: userName} = user; # rename variable

# Spread operator
const arr = [...arr1, ...arr2]; # merge arrays
const obj = {...obj1, ...obj2}; # merge objects

# Rest parameters
function sum(...numbers) { # collect args
  return numbers.reduce((a, b) => a + b);
}

const name = "John";
const age = 30;
const msg = `Hello ${name}, you are ${age}`; # interpolation

# Multi-line strings
const html = `
  

    
${title}
  
`;

let x = 10; # block scoped, reassignable
const y = 20; # block scoped, constant

# ES6 Classes
class Person {
  constructor(name) {
    this.name = name;
  }
  greet() {
    return `Hello ${this.name}`;
  }
}