fn main() {
    let mut vec = vec![10, 20];

    println!("{vec:?}");

    vec.push(30);
    println!("{vec:?}");

    println!("middle value: {}", vec[vec.len() / 2]);

    println!("vec.iter()");
    for item in vec.iter() {
        println!(" - {item}");
    }
    

    let a = vec.pop();
    println!("popped out {a:?}");
    println!("{vec:?}");
}