循环控制

Rust 中有三个循环关键字：while、loop 和 for：

while

The while keyword works much like in other languages, executing the loop body as long as the condition is true.

1. fn main() {
2. let mut x = 200;
3. while x >= 10 {
4. x = x / 2;
5. }
6. println!("Final x: {x}");
7. }