从数组的值声明联合类型

Question

export const files = ['a', 'b', 'c']

export type File = 'a' | 'b' | 'c'

如何在不重复 'a', 'b', 'c' 之类的值的情况下声明此文件类型。

Answer 1

您可以使用typeof 和number 作为索引语法。请注意，数组定义中需要 as const：

export const files = ['a', 'b', 'c'] as const;
export type File = typeof files[number];

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