Reverse
题目
Github: Reverse
实现类型版本的数组反转 Array.reverse
type a = Reverse<['a', 'b']> // ['b', 'a']
type b = Reverse<['a', 'b', 'c']> // ['c', 'b', 'a']解题思路
略。
答案
type Reverse<T extends unknown[]> = T extends [infer L, ...infer O]
? [...Reverse<O>, L]
: T验证
type cases = [
Expect<Equal<Reverse<[]>, []>>,
Expect<Equal<Reverse<['a', 'b']>, ['b', 'a']>>,
Expect<Equal<Reverse<['a', 'b', 'c']>, ['c', 'b', 'a']>>,
]
type errors = [
// @ts-expect-error
Reverse<'string'>,
// @ts-expect-error
Reverse<{ key: 'value' }>,
]