枚举

enum Role {
    Reporter,
    Developer,
    Maintainer,
    Owner,
    Guest
}
// 0
console.log(Role.Reporter);
// Reporter
console.log(Role[0]);

enum Messade {
    Success = '恭喜你，成功了',
    Fail = "抱歉，失败了"
}
// '恭喜你，成功了'
console.log(Messade.Success);

enum Char {
    //const
    a,
    b = Char.a,
    c = 1 + 3,
    //computend
    d = Math.random(),
    e = '123'.length
}

const enum Month {
    Jan,
    Fed,
    Mar
}
let month = [Month.Jan, Month.Fed, Month.Mar]
//  [0, 1, 2]
console.log(month);