在 Rust 语言中将字符串解析为无符号的问题

Question

This is the code I have:

fn main() {
  use std::io::stdin;
  let mut s=String::new();
  stdin().read_line(&mut s).expect("Wrong input");
  let n = s.parse::<u32>();
  println!("Try: {:?}", n);
}

I get no error while compiling, but it prints this in running time:

Err(ParseIntError { kind: InvalidDigit })

Answer 1

You have a trailing \n in your string, use String::trim_end :

fn main() {
  let n = "10\n".trim_end().parse::<u32>();
  println!("Try: {:?}", n);
}

From BufRead::read_line documentation :

This function will read bytes from the underlying stream until the newline delimiter (the 0xA byte) or EOF is found. Once found, all bytes up to, and including, the delimiter (if found) will be appended to buf.