面试题：Rust中枚举类型与模式匹配基础应用

Question

请用Rust编写一个枚举类型 `TrafficLight`，它有三个变体：`Red`、`Yellow`、`Green`。然后通过模式匹配，当变体为 `Red` 时输出 "Stop"，`Yellow` 时输出 "Prepare to stop"，`Green` 时输出 "Go"。

Answer 1

enum TrafficLight {
    Red,
    Yellow,
    Green,
}

fn main() {
    let light = TrafficLight::Red;
    match light {
        TrafficLight::Red => println!("Stop"),
        TrafficLight::Yellow => println!("Prepare to stop"),
        TrafficLight::Green => println!("Go"),
    }
}