// Declare some variables
let x = 42;
let mut y = "Hello, world!";
let z: f64 = 3.14;

// Print them out
println!("x: {}", x);
println!("y: {}", y);
println!("z: {}", z);

// Allocate memory dynamically
let mut v = Vec::new();

// Push some values onto the vector
v.push(1);
v.push(2);
v.push(3);

// Pop a value off the vector
let popped = v.pop();

println!("Popped value: {:?}", popped);

// Create a string
let mut s = String::from("hello");

// Pass a reference to the string
let len = calculate_length(&s);

// Define a function that borrows a string
fn calculate_length(s: &String) -> usize {
    s.len()
}

println!("Length of '{}' is {}.", s, len);