# Block-scoped variables
let x = 10;  # Can be reassigned
const y = 20;  # Cannot be reassigned

# Const with objects
const obj = {name: "John"};
obj.name = "Jane";  # OK - modifying property
obj = {};  # ERROR - cannot reassign

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

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

# With multiple statements
const greet = (name) => {
    const msg = `Hello, ${name}!`;
    return msg;
};

# Template strings
const name = "Alice";
const greeting = `Hello, ${name}!`;

# Multi-line strings
const html = `
  

    
Title
  
`;

# Expression evaluation
`Sum: ${2 + 2}`  # "Sum: 4"

# Array destructuring
const [a, b, c] = [1, 2, 3];
const [first, ...rest] = [1, 2, 3, 4];

# Object destructuring
const {name, age} = {name: "Bob", age: 30};
const {name: userName} = user;  # Rename
const {name = "Guest"} = user;  # Default value