IsPalindrome

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题目

Implement type IsPalindrome<T> to check whether a string or number is palindrome.

For example:

IsPalindrome<"abc">; // false
IsPalindrome<121>; // true

解答

type StringToTuple<T extends string> = T extends `${infer F}${infer R}`
  ? [F, ...StringToTuple<R>]
  : [];

type IsIsPalindromeArray<T extends any[]> = T extends [
  infer F,
  ...infer M,
  infer L
]
  ? F extends L
    ? IsIsPalindromeArray<M>
    : false
  : true;

type IsPalindrome<T extends string | number> = IsIsPalindromeArray<
  StringToTuple<`${T}`>
>;