5310 - Join

5310 - Join

by Pineapple (@Pineapple0919) #中等 #array

题目

Implement the type version of Array.join, Join<T, U> takes an Array T, string or number U and returns the Array T with U stitching up.

type Res = Join<["a", "p", "p", "l", "e"], "-">; // expected to be 'a-p-p-l-e'
type Res1 = Join<["Hello", "World"], " ">; // expected to be 'Hello World'
type Res2 = Join<["2", "2", "2"], 1>; // expected to be '21212'
type Res3 = Join<["o"], "u">; // expected to be 'o'

在 Github 上查看：https://tsch.js.org/5310/zh-CN

代码

/* _____________ 你的代码 _____________ */

type Join<T extends string[], U extends string | number = ','> =
  T extends [infer L extends string, ...infer R extends string[]]
    ? R['length'] extends 0
      ? L
      : `${L}${U}${Join<R, U>}`
    : ''

测试用例

/* _____________ 测试用例 _____________ */
import type { Equal, Expect } from '@type-challenges/utils'

type cases = [
  Expect<Equal<Join<['a', 'p', 'p', 'l', 'e'], '-'>, 'a-p-p-l-e'>>,
  Expect<Equal<Join<['Hello', 'World'], ' '>, 'Hello World'>>,
  Expect<Equal<Join<['2', '2', '2'], 1>, '21212'>>,
  Expect<Equal<Join<['o'], 'u'>, 'o'>>,
  Expect<Equal<Join<[], 'u'>, ''>>,
  Expect<Equal<Join<['1', '1', '1']>, '1,1,1'>>,
]

相关链接

分享你的解答：https://tsch.js.org/5310/answer/zh-CN
查看解答：https://tsch.js.org/5310/solutions
更多题目：https://tsch.js.org/zh-CN