L0v3ch4n

外观

Replace Union

约 120 字小于 1 分钟

2026-02-11

题目

Given an union of types and array of type pairs to replace ([[string, number], [Date, null]]), return a new union replaced with the type pairs.

解题思路

待补充

答案

type UnionReplace<T, U extends [any, any][]> = any

验证

import type { Equal, Expect } from '@type-challenges/utils'

type cases = [
  // string -> null
  Expect<Equal<UnionReplace<number | string, [[string, null]]>, number | null>>,

  // string -> null
  Expect<Equal<UnionReplace<number | string, [[string, null], [Date, Function]]>, number | null>>,

  // Date -> string; Function -> undefined
  Expect<Equal<UnionReplace<Function | Date | object, [[Date, string], [Function, undefined]]>, undefined | string | object>>,
]

参考

无