TypeScript Type Challenges Medium_配列操作系

Tuple to Union

https://github.com/type-challenges/type-challenges/blob/main/questions/00010-medium-tuple-to-union/README.md

code:typescript

type TupleToUnion<T extends any[]> = Tnumber

Answer

Last of Array

https://github.com/type-challenges/type-challenges/blob/main/questions/00015-medium-last/README.md

code:typescript

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

// 解2

type Last2<T extends any[]> = any, ...T[T'length']

Answer

Pop

https://github.com/type-challenges/type-challenges/blob/main/questions/00016-medium-pop/README.md

code:typescript

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

Answer

Shift

https://github.com/type-challenges/type-challenges/blob/main/questions/03062-medium-shift/README.md

Popとほぼ同じ

Reverse

https://github.com/type-challenges/type-challenges/blob/main/questions/03192-medium-reverse/README.md

Chunk

https://github.com/type-challenges/type-challenges/blob/main/questions/04499-medium-chunk/README.md

Fill

https://github.com/type-challenges/type-challenges/blob/main/questions/04518-medium-fill/README.md

wintyo.icon 範囲指定が難しい

Without

https://github.com/type-challenges/type-challenges/blob/main/questions/05117-medium-without/README.md

omitのタプル版

Flatten

https://github.com/type-challenges/type-challenges/blob/main/questions/00459-medium-flatten/README.md

ネストされた配列を全部無くす

wintyo.icon 再帰で多分なんとかなる

Flatten Depth

https://github.com/type-challenges/type-challenges/blob/main/questions/03243-medium-flattendepth/README.md

flattenに階層を指定する

/icons/hr.icon

タプルから特定のフィールドをpickする

code:typescript

type TabItem = {

value: string;

label: string;

}

const TAB_ITEMS = [

{ value: 'tab1', label: 'タブ１' },

{ value: 'tab2', label: 'タブ２' },

{ value: 'tab3', label: 'タブ３' },

] as const satisfies TabItem[];

type PickTabValues<Arr extends readonly TabItem[]> =

Arr extends readonly [infer Item extends TabItem, ...infer Rest extends TabItem[]]

? [Item'value', ...PickTabValues<Rest>]

: []

const pickTabValues = <Arr extends readonly TabItem[]>(tabItems: Arr): PickTabValues<Arr> => {

return tabItems.map((tabItem) => tabItem.value) as PickTabValues<Arr>

}

const tabValues = pickTabValues(TAB_ITEMS)

コード

#TypeScript_Type_Challenges