Typescript enum, array as value-CodePudding

This looks odd to me

enum MessageStatusGroup {
  PENDING = [1, 2, 3],
  PUBLISHED = [4],
  DRAFT = [0],
}

and my linter gives error

Is there any limitation in typescript that prevents specifing array as value?

CodePudding user response：

jna and TBA are right.

But may be you can simply workaround with :

export const MessageStatusGroup = {
  PENDING : [1, 2, 3],
  PUBLISHED : [4],
  DRAFT : [0],
} as const;

It should do the trick. The 'as const' at the end will ensure immutability of MessageStatusGroup, then it can be used the same way as an enum.

CodePudding user response：

Short answer is that TypeScript support numeric and string-based enums, array are not supported.

CodePudding user response：

Yes, in TypeScript enums, the values must be either string or number types. An array is not a valid value. This is why your linter is giving an error.

TypeScript provides both numeric and string-based enums.

Third line here

You can also point to other enums

enum Foo {
  Bar = 'Baz'
}

enum PointTo {
  Bar = Foo.Bar
}

And for numeric enums, you can also point to functions that return numeric values.

const numFunc = () => 4;

enum PointTo {
  Function = numFunc()
}

Check out typescriptlang for more examples