trpl-zh-cn/listings/ch02-guessing-game-tutorial/listing-02-05/src/main.rs

use rand::Rng;
use std::cmp::Ordering;
use std::io;

fn main() {
    println!("Guess the number!");

    let secret_number = rand::thread_rng().gen_range(1..101);

    println!("The secret number is: {}", secret_number);

    loop {
        println!("Please input your guess.");

        let mut guess = String::new();

        // ANCHOR: here
        // --snip--

        io::stdin()
            .read_line(&mut guess)
            .expect("Failed to read line");

        // ANCHOR: ch19
        let guess: u32 = match guess.trim().parse() {
            Ok(num) => num,
            Err(_) => continue,
        };
        // ANCHOR_END: ch19

        println!("You guessed: {}", guess);

        // --snip--
        // ANCHOR_END: here

        match guess.cmp(&secret_number) {
            Ordering::Less => println!("Too small!"),
            Ordering::Greater => println!("Too big!"),
            Ordering::Equal => {
                println!("You win!");
                break;
            }
        }
    }
}