type-challenges-judge

Type Challenges Judge

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StartsWith

提出詳細

type StartsWith<T extends string, U extends string, A extends string = ""> =
  T extends `${infer Head}${infer Rest}` ? A extends U ? true : StartsWith<Rest, U, `${A}${Head}`> : false

提出日時	2025-09-16 04:38:55
問題	StartsWith
ユーザー	balckowl
ステータス	Accepted

テストケース

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

type cases = [
  Expect<Equal<StartsWith<'abc', 'ac'>, false>>,
  Expect<Equal<StartsWith<'abc', 'ab'>, true>>,
  Expect<Equal<StartsWith<'abc', 'abcd'>, false>>,
  Expect<Equal<StartsWith<'abc', ''>, true>>,
  Expect<Equal<StartsWith<'abc', ' '>, false>>,
]