这个问题在这里已有答案:
我刚刚开始尝试Rust,所以我已经实现了Book的“猜测游戏”中的修改版本。每次第一次尝试输入数字时,程序都无法解析字符串中的整数:
Guess the number!
Input your guess:
50
You guessed 50
(4 bytes)!
thread 'main' panicked at 'Wrong number format!: ParseIntError { kind: InvalidDigit }', src\libcore\result.rs:997:5
note: Run with `RUST_BACKTRACE=1` environment variable to display a backtrace.
error: process didn't exit successfully: `target\release\experiment.exe` (exit code: 101)
代码如下。
我已经尝试过其他整数类型。
use std::io;
use rand::Rng;
fn main() {
println!("Guess the number!\nInput your guess:");
let mut guess = String::new();
let secnum = rand::thread_rng().gen_range(1,101);
'br: loop {
match io::stdin().read_line(&mut guess) {
Ok(okay) => {
println!("You guessed {} ({} bytes)!", guess, okay);
let intguess = guess.parse::<u8>()
.expect("Wrong number format!");
match secnum.cmp(&intguess) {
std::cmp::Ordering::Less => {
println!("Your guess is smaller!");
}
std::cmp::Ordering::Greater => {
println!("Your guess is bigger!");
}
std::cmp::Ordering::Equal => {
println!("You guessed right!");
break 'br;
}
}
}
Err(erro) => {
println!("Failed to read the line: {}!", erro);
}
}
}
}
read_line
的字符串输出包含一个尾随的换行符,因此您需要将其删除以解析该数字。您可以使用trim_end (or just
trim`来处理前导空格):
let guess: u8 = guess
.trim_end()
.parse()
.expect("Wrong number format!");