Rust 程式設計視訊教程對應講解內容－結構體

頭條地址：https://www.ixigua.com/i676544267458235648...
Ｂ站地址：https://www.bilibili.com/video/av78062009?...
網易雲課堂地址：https://study.163.com/course/introduction....

1、定義結構體

struct User {
    username: String,
    email: String,
    sign_in_count: u64,
    active: bool,
}

2、建立結構體例項

let user1 = User {
    email: String::from("someone@example.com"),
    username: String::from("someusername123"),
    active: true,
    sign_in_count: 1,
};

3、修改結構體欄位

let mut user1 = User {
    email: String::from("someone@example.com"),
    username: String::from("someusername123"),
    active: true,
    sign_in_count: 1,
};

user1.sign_in_count = 3；

4、引數名字和欄位名字同名的簡寫方法

fn build_user(email: String, username: String) -> User {
    User {
        email,
        username,
        active: true,
        sign_in_count: 1,
    }
}

5、從其它結構體建立例項
正常寫法：

let user2 = User {
    email: String::from("another@example.com"),
    username: String::from("anotherusername567"),
    active: user1.active,
    sign_in_count: user1.sign_in_count,
};

簡寫方法：

let user2 = User {
    email: String::from("another@example.com"),
    username: String::from("anotherusername567"),
    ..user1
};

6、元組結構體
特點：
（1）欄位沒有名字
（2）圓括號

struct Color(i32, i32, i32);
struct Point(i32, i32, i32);
let black = Color(0, 0, 0);
let origin = Point(0, 0, 0);

7、沒有任何欄位的類單元結構體
用於在其上實現trait，類似於定義一個沒有成員的類，但是有成員函式。

8、列印結構體

#[derive(Debug)]       //新增deprive(Debug)支援列印
struct Rectangle {
    width: u32,
    height: u32,
}

fn main() {
    let rect1 = Rectangle { width: 30, height: 50 };
    println!("rect1 is {:?}", rect1);
}