Rust学习笔记

Rust编程语言入门教程课程笔记

参考教材: The Rust Programming Language (by Steve Klabnik and Carol Nichols, with contributions from the Rust Community)

Lecture 1: Getting Started

hello_world.rs

fn main(){println!("Hello World!"); // "!" means "println!" is a rust macro
}// compile: rustc hello_world.rs
// run: ./hello_world

hello_cargo.rs

fn main() {println!("Hello, cargo!");
}//new project: cargo new hello_cargo
//src: main.rs 
//cargo.toml: project metadata
//check: cargo check
//build: cargo build -> target/debug/hello_cargo
//build: cargo build --release -> target/release/hello_cargo
//run: cargo run

Lecture 2: Programming a Guessing Game

use std::io; //io library
use std::cmp::Ordering; //cmp method
use rand::Rng; //rand libraryfn main() {let secret_number = rand::thread_rng().gen_range(1..=100); //gen_range method of rand::thread_rng()println!("Guess the number!");loop {println!("Please input your guess.");let mut guess = String::new(); //String type is in prelude//guess is a mutable variableio::stdin() //io library.read_line(&mut guess) //read_line returns a value of type io::Result.expect("Failed to read line"); //expect method of io::Result//io.Result is an enum//io.Result has variants: Ok and Err//Ok: the value inside is the result of the successful operation//Err: the value inside is the Err infomationlet guess:u32 = match guess.trim().parse(){//shadowingOk(num) => num,Err(_) => continue,};println!("You guessed: {}", guess);match guess.cmp(&secret_number) { //cmp method of the type String//cmp method compares two values and can be called on anything that can be compared//cmp method returns a variant of Ordering enum//Ordering enum has variants: Less, Greater, EqualOrdering::Less => println!("Too small!"),Ordering::Greater => println!("Too big!"),Ordering::Equal => {println!("You win!");break;}}}}