AI solution for TypeScript puzzle on BFE.dev
23. implement LengthOfTuple<T>

Solution:

type LengthOfTuple<T extends any[]> = T['length'];

type A = LengthOfTuple<['B', 'F', 'E']>; // 3
type B = LengthOfTuple<[]>; // 0

Explanation:

• We define a generic type T extends any[] that extends any array.
• We use the length property of type T to get its length and return it as the result of LengthOfTuple<T>.

Note:

• The any keyword is used here to represent any type, including primitive types like string, number, etc. and object types.