如何将字符串数组转换为typescript类型？ [英] How to convert array of strings to typescript types?

问题描述

我有这个数组：

const arr = ["foo", "bar", "loo"]

我需要将其转换为打字稿类型

I need to convert it to a typescript type

type arrTyp = "foo" | "bar" | "loo";

我怎样才能在打字稿中这样做？

How can I do this in typescript?

推荐答案

问题是 arr 不保留数组中的文字类型，它将被引用到串[] 。如果你使用一个函数强制推断字符串文字类型，提取类型是一件简单的事情：

The problem is that arr does not preserve the literal types in the array, it will be infered to string[]. If you use a function to force the inference of string literal type, extracting the type is a simple affair:

function tuple<T extends string[]>(...o: T) {
    return o;
}
const arr = tuple("foo", "bar", "loo")

type arrTyp = typeof arr[number]; // "foo" | "bar" | "loo"

该函数强制编译器为 ARR 。所以 arr 将被输入 [foo，bar，loo] 。然后我们可以使用类型查询来获取元组中元素的并集。您可以在此处

The function forces the compiler to infer a tuple of string literals for arr. So arr will be typed as ["foo", "bar", "loo"]. We can then use a type query to get a union of the elements in the tuple. You can read more about type queries here

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