loop expressions

Finally, there is a loop keyword which creates an endless loop. Here you must either break or return to stop the loop:

  1. fn main() {
  2.     let mut x = 10;
  3.     loop {
  4.         x = if x % 2 == 0 {
  5.             x / 2
  6.         } else {
  7.             3 * x + 1
  8.         };
  9.         if x == 1 {
  10.             break;
  11.         }
  12.     }
  13.     println!("Final x: {x}");
  14. }
  • Break the loop with a value (e.g. break 8) and print it out.