• 새 프로젝트 준비하기

  cargo new guessing_game --bin
  

기본 뼈대

use std::io;

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

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

    let mut guess = String::new();

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

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

• use: 라이브러리를 스코프로 가져오기.

• let은 변수 할당

  • 불변 변수

    let foo = 3;
    

  • 가변 변수

    let mut bar = 3;
    

  전체 코드

  extern crate rand;
  
  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);
  
      loop {
          println!("Please input your guess.");
  
          let mut guess = String::new();
  
          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;
              }
          }
      }
  }