wiki/content/20200827190443-rust_control_flow.md

date	id	title
20200827	0ae97b2d-5a3c-40b5-9ce1-37aacb647c5d	Rust control flow

Branching

If

fn main() {
    let number = 3;

    if number < 5 {
        println!("condition was true");
    } else {
        println!("condition was false");
    }
}

Because Rust is expressive we can use an `if` expression on the right side of a `let` statement:

fn main() {
    let condition = true;
    let number = if condition { 5 } else { 6 };

    println!("The value of number is: {}", number);
}

Loops

Loop

This will loop forever

fn main() {
    loop {
        println!("again!");
    }
}

Loops can also return values:

fn main() {
    let mut counter = 0;

    let result = loop {
        counter += 1;

        if counter == 10 {
            break counter * 2;
        }
    };

    println!("The result is {}", result);
}

While

Rust also supports while loops:

fn main() {
    let mut number = 3;

    while number != 0 {
        println!("{}!", number);

        number -= 1;
    }

    println!("LIFTOFF!!!");
}

For

For loops are supported as well

fn main() {
    let a = [10, 20, 30, 40, 50];

    for element in a.iter() {
        println!("the value is: {}", element);
    }
}