rust代码学习笔记（未完待续10/31）

news2024/9/21 14:36:17

文章目录

- 一、案例一：读取输入打印出来
- 二、案例二：（引入新包）猜数字游戏
- 三、案例三：循环猜测数字
- 四、案例四：猜字游戏（彩色版本）
- 五、rust一些注意事项
- - 1）声明变量默认是不可修改的
  - 2）const定义常量,且必须加类型标注
  - 3）标量（scalar）和复合类型（compound）数据类型
- 六、函数
- 七、控制流程（if、else语句和while语句、for循环）

一、案例一：读取输入打印出来

fn main() {
    println!("Hello, world!");
    let mut guess = String::new();
    io::stdin().read_line(&mut guess).expect("error");

    println!("你打印的数字是  {}",guess);
}

二、案例二：（引入新包）猜数字游戏

cargo build 安装新包

①引入随机数包
在这里插入图片描述
②引入随机库
③源码

use std::io; //需要引入库
use rand::Rng;
use std::cmp::Ordering;

fn main() {

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

    println!("请输入你的猜测数字!");

    let mut guess = String::new();
    io::stdin().read_line(&mut guess).expect("error");
    let guess:i32 = guess.trim().parse().expect("请输出数字");

    match guess.cmp(&secret_num){
        Ordering::Less     =>println!("猜小了"),
        Ordering::Greater  =>println!("猜大了"),
        Ordering::Equal    =>println!("猜对了"),
    }

    println!("你输入的数字是  {}",guess);
    print!("秘密数字是:{}",secret_num);
}

三、案例三：循环猜测数字

use std::io; //需要引入库
use rand::Rng;
use std::cmp::Ordering;

fn main() {

    let secret_num=rand::thread_rng().gen_range(1..101);
    loop {
        println!("请输入你的猜测数字!");

        let mut guess = String::new();
        io::stdin().read_line(&mut guess).expect("error");
        let guess:i32 = match guess.trim().parse(){
            Ok(num)  =>num,
            Err(_)       =>continue,
        };
    
        match guess.cmp(&secret_num){
            Ordering::Less     =>println!("猜小了"),
            Ordering::Greater  =>println!("猜大了"),
            Ordering::Equal    =>{
                println!("猜对了");
                break;
            },
        }
    
        println!("你输入的数字是  {}",guess);
        print!("秘密数字是:{}",secret_num);
    }
}

四、案例四：猜字游戏（彩色版本）

use std::io; //需要引入库
use rand::Rng;
use std::cmp::Ordering;
use colored::*;

fn main() {

    let secret_num=rand::thread_rng().gen_range(1..101);
    loop {
        println!("请输入你的猜测数字!");

        let mut guess = String::new();
        io::stdin().read_line(&mut guess).expect("error");
        let guess:i32 = match guess.trim().parse(){
            Ok(num)  =>num,
            Err(_)       =>continue,
        };
    
        match guess.cmp(&secret_num){
            Ordering::Less     =>println!("{}","太小了！".red()),
            Ordering::Greater  =>println!("{}","太大了！".red()),
            Ordering::Equal    =>{
                println!("{}","猜对了!".green());
                break;
            },
        }
    
        println!("你输入的数字是  {}",guess);
        print!("秘密数字是:{}",secret_num);
    }
}