type Pop<T extends any[]> = T extends [] 
  ? [] 
  : T extends [...infer Rest, any] 
    ? Rest 
    : never

Solution by eunsukimme #35123

type Pop<T extends any[]> = T extends [...infer F, infer L] ? [...F] : never;

Solution by raeyoung-kim #35001

type Pop<T extends any[]> = T extends never[] ? [] : T extends [...infer R, any] ? R: never

Solution by 56aiden90 #34956

// your answers
type Pop<T extends any[]> = T extends [...infer P, any] ? P : T;

Solution by zeyuanHong0 #34803

type Pop<T extends any[]> = T extends [...infer R, infer _] ? R : []

Solution by YBFJ #34682

type Pop<T extends any[]> = T extends [...infer A,infer B] ? [...A] : []

Solution by devshinthant #34566

type Pop<T extends unknown[]> = T extends [] ? [] : (T extends [...infer P, infer R] ? P : never);

对于[]的情况需要进行特殊判定，尝试过多种解决方案，不加[]做特殊判定的分支情况下，在泛型中采用any[]和unknown[]都无法通过。

Solution by wxh-cyber #34490

// your answers
type Pop<T extends any[]> = T extends [] ? [] :  T extends [...infer P, infer _X] ? P : never

Solution by gobielJonathan #34472

type Pop<T extends any[]> = T extends [...infer R, infer L] ? R : [];

Solution by ktim816 #34444

type Pop<T extends any[]> = T extends [infer A, infer B, ...infer Rest] 
  ? Rest['length'] extends 0 ? [A] : [A, ...Pop<[B, ...Rest]>]
  : []

Solution by rookie-luochao #34388

// 你的答案

type Pop<T extends any[]> = T extends [...infer A, infer B] ? A : []

Solution by W-fitTiger #34256

문제 설명

이 챌린지에는 TypeScript 4.0 사용이 권장됩니다.

배열 T를 사용해 마지막 요소를 제외한 배열을 반환하는 제네릭 Pop<T>를 구현합니다.

예시

type arr1 = ["a", "b", "c", "d"];
type arr2 = [3, 2, 1];

type re1 = Pop<arr1>; // expected to be ['a', 'b', 'c']
type re2 = Pop<arr2>; // expected to be [3, 2]

풀이

앞선 문제였던 Last 문제와 아주 유사한 문제였습니다. 타입을 추론하는 infer를 사용하여 해결합니다.

solution

type Pop<T extends any[]> = T extends [...infer Rest, infer Last]
	? [...Rest]
	: [];

/* _____________ 테스트 케이스 _____________ */
import type { Equal, Expect } from "@type-challenges/utils";

type cases = [
	Expect<Equal<Pop<[3, 2, 1]>, [3, 2]>>,
	Expect<Equal<Pop<["a", "b", "c", "d"]>, ["a", "b", "c"]>>,
	Expect<Equal<Pop<[]>, []>>
];

Solution by adultlee #34156

type Pop<T extends any[]> = T extends [...infer ANY, infer L] ? ANY : T;

Solution by G00syara #34041

type Pop<T extends any[]> =  T['length'] extends 0 ? T : T extends [...infer P, any] ? P : never

Solution by ouzexi #33990

type Pop<T extends any[]> = T extends [...args: infer R, any] ? R : []

Solution by Mumujianguang #33956

type Pop<T extends any[]> = T extends [...infer R, infer S] ? R : [];

Solution by ckdwns9121 #33953

type Pop<T extends any[]> = T extends [...infer Rest, infer _] ? Rest : []

Solution by notsecret32 #33892

type Pop<T extends Array<unknown>> = T extends [...infer R, infer P] ? R : never
type Push<T extends Array<unknown>, U> = [...T, U]
type Shift<T extends Array<unknown>> = T extends [infer R, ...infer P] ? P : never
type Unshift<T extends Array<unknown>, U> = [U, ...T]

Solution by Danny101201 #33833

type Pop<T extends any[]> = T extends [...infer Rest, any] ? Rest : []

Solution by laplace1009 #33719

type Pop<T extends any[]> = T['length'] extends 0 ? [] : T extends [...infer P, infer L] ? (L extends never ? [] : P) : never;

Solution by nupthale #33582

// 你的答案
type Pop<T extends any[]> = T extends [] ? [] : T extends [...infer F, infer L] ? F : never

Solution by shaobeichen #33375

type Pop<T extends any[]> = T extends [] ? [] 
      : T extends [...infer R, infer L] ? R : never

Solution by naoxin20040419 #33364

type Pop<T extends any[]> = T extends [...infer P, unknown] ? P : []

Solution by loevray #33260

type Pop<T extends Array<any>> = T extends [...infer R, any] ? R : never; 
type push<T extends any[],K> = [...T,K];
type shift<T> = T extends [any,...infer R] ? R : never; 
type unshift<T extends any[],R extends any[]|string|number> = R extends Array<any> ?[ ...R ,...T] : [R,...T];

Solution by fffqwhy #32955

type Pop<T extends any[]> = T extends [...infer R, infer _] ? [...R] : [];

type Push<T extends any[], V> = [...T, V];
type Shift<T extends any[]> = T extends [infer _, ...infer R] ? R : never;
type Unshift<T extends any[], V> = [V, ...T];

Solution by juffyduan #32946

// 你的答案
type Pop<T extends any[],R extends any[] = []> = T extends [infer F,...infer O] ? O extends [] ? R : Pop<O,[...R,F]>
:[]

Solution by walker-hzx #32936

type Pop<T extends any[]> = T extends [...infer S, infer U] ? S : never;

Solution by CAN1177 #32869

// 解答をここに記入
type Pop<T extends any[]> = T extends []
  ? []
  : T extends [...infer A, any]
    ? [...A]
    : never;

空配列の可能性があるため、まず空配列かどうかを判定。
空配列では無いなら、最後の要素以外をinfer Aに集約し返却。

Solution by Yasunori-aloha #32825

type Pop<T extends any[]> = T['length'] extends 0 ? [] : T extends [...infer F, infer L] ? F : never;

Solution by ZhipengYang0605 #32799

type Pop<T> = T extends [...infer R , infer _] ? [...R] : [];

Solution by malyanoff #32780

00016-medium-pop

문제 설명

풀이

solution