Rust Book Guessing修改游戏查询

Question

我修改了Rust Book Guessing Game Tutorial中的代码，使其更短；幻灯片。 las，我介绍了一个错误。防范这种情况的最佳方法是什么？

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

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

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

    let mut guess = String::new();

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

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

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

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

Answer 1

read_line会将行追加到缓冲区，因此您的guess将累加所有输入！在循环内移动let mut guess = String::new();解决了问题：

fn main() {
    ...

    loop {
        let mut guess = String::new();

        ...
    }
}