[control-flow] finished section

    println!("{x}, {y}");

    // here's how to do a loop

    // loop {

    //     println!("again!");

    // }

    let mut counter = 0;

    let result = loop {

        counter += 1;

        if counter == 10 {

            break counter + 2; // result == 10 + 2 == 12

        }

    };

    println!("The result of counter is {result}"); // and 12 will print here

    println!("labeled loop \'counting_up");

    let mut count = 0;

    'counting_up: loop {

        println!("count = {count}");

        let mut remaining = 10;

        loop {

        println!("again!");

            println!("remaining = {remaining}");

            if remaining == 9 {

                break;

            }

            if count == 2 {

                break 'counting_up;

            }

            remaining -= 1;

        }

        count += 1;

    }

    println!("End count = {count}");

    println!("while loop");

    let mut number = 3;

    while number != 0 {

        println!("{number}");

        number -= 1;

    }

    println!("LIFTOFF!!");

    println!("looping through a collection with \"for\"");

    let a = [10, 20, 30, 40, 50];

    let mut index = 0;

    while index < 5 {

        println!("a[{index}] is {}", a[index]);

        index += 1;

    }

    // can also do

    for element in a {

        println!("the value is: {element}");

    }

    println!("here is a better liftoff implementation");

    for number in (1..4).rev() {

        println!("{number}!");

    }

    println!("LIFTOFF!!!");

}