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116 - Replace

Answer TestCases

实现 Replace<S, From, To> 将字符串 S 中的第一个子字符串 From 替换为 To 。

例如

type replaced = Replace<'types are fun!', 'fun', 'awesome'> // 期望是 'types are awesome!'

Solution

type Replace<
  S extends string,
  From extends string,
  To extends string
> = From extends ''
  ? S
  : S extends `${infer V}${From}${infer R}`
  ? `${V}${To}${R}`
  : S

From 为空则直接返回原字符串类型, 不为空则执行

S extends`${infer V}${From}${infer R}`

通过 infer 关键字对原字符串进行类型分离, 找出 From 后替换为 To

Solution