Rust——枚举

当一个变量有几种确定的取值情况下，可以将它定义为枚举类型。如性别选择(男/女)

通过      枚举名::枚举值     来访问获取枚举值

1.无参数枚举类型

　　

#[derive(Debug)]
enum Sex{     //无参数枚举类型
    male,
    female,
}

fn main(){
    let lilei = Sex::male;
    let lily = Sex::female;
　　　//结构体/枚举类型输出均{:?}
    println!("lilei is a {:?} and lily is a {:?}",lilei,lily);
}

 输出结果：

 

2.含参数枚举类型

 　　区别于无参数枚举类型地方是，可以给枚举成员添加  元组属性

　　

#[derive(Debug)]
enum PayAccount{      ///支付帐号,带参数枚举类型
    AlipayAccount(String),
    WechatAccount(String),
    BankAccount(u64),
}

enum People{      ///带参数枚举类型
    ChinesePeople{nation:String,totalnumber:u128},
    AmericanPeople{totalnumber:u128},
    JapanesePeople{height:f64},
}



fn main(){
    let _alibaba = PayAccount::AlipayAccount(String::from("efun@qq.com"));
    let _wechat = PayAccount::WechatAccount(String::from("onlyefun"));
    let _bank = PayAccount::BankAccount(111122223333444);

    let zhonghuijie = People::ChinesePeople{
        nation:String::from("han"),totalnumber:14_000_000_000_000_000};
    


    match zhonghuijie{
        People::AmericanPeople{totalnumber}=>{
            println!("American number is {}",totalnumber);
        },
        People::ChinesePeople{nation,totalnumber}=>{
            println!("Chinese nation is {},totalnumber is {}",nation,totalnumber);
        },
        People::JapanesePeople{height}=>{
            println!("Japanese height is {}",height);
        }
    }
    println!("alibaba account is {:#?}",_alibaba);
    
    println!("Run End");
}

运行结果：

　　

 

以上代码在VS Code中运行，结果如下：

 

 中间少了邮箱地址邮件地址显示

 

去掉字符@后，正常显示