[易学易懂系列|rustlang语言|零基础|快速入门|(11)|Structs结构体]
2024-09-04 05:22:38
[易学易懂系列|rustlang语言|零基础|快速入门|(11)]
有意思的基础知识
Structs
我们今天来看看数据结构:structs.
简单来说,structs,就是用来封装相关数据的一种数据类型。
一般来说, struct 的命名方式为驼峰方式如: CamelCase
在Rust有以下几种定义struct的方式:
- C-like structs (C语言形式的struct)
- Tuple structs (元组形式的struct)
- Unit structs (单元struct)
在Rust,面向对象抽象,一般由struct和trait(特征)来实现,即structs来
封装属性数据,而trait用来封装方式,再由impl来关联。
我们来看看代码:
C语言形式的struct
// Struct Declaration
struct Color {
red: u8,
green: u8,
blue: u8
}
fn main() {
// Creating an instance
let black = Color {red: 0, green: 0, blue: 0};
// Accessing its fields using dot notation
println!("Black = rgb({}, {}, {})", black.red, black.green, black.blue); //Black = rgb(0, 0, 0)
// Structs are immutable by default, use `mut` to make it mutable but doesn't support field level mutability
let mut link_color = Color {red: 0,green: 0,blue: 255};
link_color.blue = 238;
println!("Link Color = rgb({}, {}, {})", link_color.red, link_color.green, link_color.blue); //Link Color = rgb(0, 0, 238)
// Copy elements from another instance
let blue = Color {blue: 255, .. link_color};
println!("Blue = rgb({}, {}, {})", blue.red, blue.green, blue.blue); //Blue = rgb(0, 0, 255)
// Destructure the instance using a `let` binding, this will not destruct blue instance
let Color {red: r, green: g, blue: b} = blue;
println!("Blue = rgb({}, {}, {})", r, g, b); //Blue = rgb(0, 0, 255)
// Creating an instance via functions & accessing its fields
let midnightblue = get_midnightblue_color();
println!("Midnight Blue = rgb({}, {}, {})", midnightblue.red, midnightblue.green, midnightblue.blue); //Midnight Blue = rgb(25, 25, 112)
// Destructure the instance using a `let` binding
let Color {red: r, green: g, blue: b} = get_midnightblue_color();
println!("Midnight Blue = rgb({}, {}, {})", r, g, b); //Midnight Blue = rgb(25, 25, 112)
}
fn get_midnightblue_color() -> Color {
Color {red: 25, green: 25, blue: 112}
}
元组形式的struct
struct Color(u8, u8, u8);
struct Kilometers(i32);
fn main() {
// Creating an instance
let black = Color(0, 0, 0);
// Destructure the instance using a `let` binding, this will not destruct black instance
let Color(r, g, b) = black;
println!("Black = rgb({}, {}, {})", r, g, b); //black = rgb(0, 0, 0);
// Newtype pattern
let distance = Kilometers(20);
// Destructure the instance using a `let` binding
let Kilometers(distance_in_km) = distance;
println!("The distance: {} km", distance_in_km); //The distance: 20 km
}
单元struct
struct Electron;
fn main() {
let x = Electron;
}
以上,希望对你有用。
如果遇到什么问题,欢迎加入:rust新手群,在这里我可以提供一些简单的帮助,加微信:360369487,注明:博客园+rust
https://learning-rust.github.io/docs/b2.structs.html
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