[2주차] Easy 풀이

[sbyeol3]

title	solved
4-pick	✅
7-read only	✅
11-tuple	🏷
14-first of array	🏷
18-length of tuple	🏷
43-exclude	✅
189-awaited	🏷
268-if	✅
533-concat	✅
898-includes	💡- myEqual
3057-push	✅
3060-unshift	✅
3312-parameters	🏷

풀이 link

✅: 해결
🏷: 해답 열람 후 다시 풀었음
💡: 다시 볼 필요 있음

[humonnom]

💡type-level equality check

1. 쌍방향 extends 체크

type Equal<T, U> = T extends U ? (U extends T ? true : false) : false;

• readonly 키워드가 쓰인 경우 !Equal

Expect<Equal<Includes<[{ a: 'A' }], { readonly a: 'A' }>, false>>,
Expect<Equal<Includes<[{ readonly a: 'A' }], { a: 'A' }>, false>>,

2.

type-level equality operator

export type Equals<X, Y> =
    (<T>() => T extends X ? 1 : 2) extends
    (<T>() => T extends Y ? 1 : 2) ? true : false;