break 和 continue

如果你想立即進入下一次迭代，可以使用 continue。

If you want to exit any kind of loop early, use break. For loop, this can take an optional expression that becomes the value of the loop expression.

fn main() {
    let mut i = 0;
    loop {
        i += 1;
        if i > 5 {
            break;
        }
        if i % 2 == 0 {
            continue;
        }
        println!("{}", i);
    }
}