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Typescript 如何在类型批注中将数字枚举用作索引？_Typescript - Fatal编程技术网
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Typescript 如何在类型批注中将数字枚举用作索引？

typescript

Typescript 如何在类型批注中将数字枚举用作索引？,typescript,Typescript,我想使用数字枚举作为对象中的索引类型 enum Weekday { Monday = 0, Tuesday = 1, Wednesday = 2, Thursday = 3, Friday = 4, Saturday = 5, Sunday = 6 }; const isWeekend: { [day: Weekday]: boolean } = { [Weekday.Monday]: false, [Weekday.Tu

我想使用数字枚举作为对象中的索引类型

enum Weekday {
    Monday = 0,
    Tuesday = 1,
    Wednesday = 2,
    Thursday = 3,
    Friday = 4,
    Saturday = 5,
    Sunday = 6
};

const isWeekend: { [day: Weekday]: boolean } = {
    [Weekday.Monday]: false,
    [Weekday.Tuesday]: false,
    [Weekday.Wednesday]: false,
    [Weekday.Thursday]: false,
    [Weekday.Friday]: false,
    [Weekday.Saturday]: true,
    [Weekday.Sunday]: true,
};
此代码无法使用消息进行类型检查：

索引签名参数类型必须为“字符串”或“数字”

我知道有几个变通办法。如果我将
isWeekend
的类型更改为
{[day:number]：boolean}
它将编译，但类型会丢失一些精度

如何在不更改
工作日
定义的情况下，为
isWeekend
提供更精确的类型？

我自己刚刚解决了这个问题。我应该在工作日使用
day
而不是
day:Weekday
。以下代码起作用：

enum Weekday {
    Monday = 0,
    Tuesday = 1,
    Wednesday = 2,
    Thursday = 3,
    Friday = 4,
    Saturday = 5,
    Sunday = 6
};

const isWeekend: { [day in Weekday]: boolean } = {
    [Weekday.Monday]: false,
    [Weekday.Tuesday]: false,
    [Weekday.Wednesday]: false,
    [Weekday.Thursday]: false,
    [Weekday.Friday]: false,
    [Weekday.Saturday]: true,
    [Weekday.Sunday]: true,
};
看起来这个建议是，，，最后是去年谢谢，通读这些建议导致了我的错误：我使用了
：Weekday
而不是在Weekday中使用
。