Typescript one of array

function stringLiterals<T extends string>(...args: T[]): T[] { return args; }
type ElementType<T extends ReadonlyArray<unknown>> = T extends ReadonlyArray<infer ElementType> ? ElementType : never;

const values = stringLiterals('A', 'B');
type Foo = ElementType<typeof values>;

const v1: Foo = 'A' // This should work
const v2: Foo = 'D' // This should give me an error since 'D' doesn't exist in values

Source: github.com

Typescript one of the array items

const animals = ['cat', 'dog', 'mouse'] as const
type Animal = typeof animals[number]

// type Animal = 'cat' | 'dog' | 'mouse'

Source: steveholgado.com

Similar codes

0 vote371 views1 answer
Config all requests to one page nginx
TypeScript
15 votes372 views2 answers
How to check if var exists python
TypeScript
27 votes355 views6 answers
Router.navigate angular
TypeScript
4 votes320 views3 answers
Find iemts in object of array mongodb
TypeScript
0 vote303 views1 answer
How to do Email validation using Regular expression in Typescript
TypeScript
5 votes302 views1 answer
Extends vs implements java
TypeScript
1 vote338 views1 answer
Sass migrate division vue
TypeScript
1 vote350 views1 answer
Git count commits by author
TypeScript
1 vote348 views2 answers
Property 'userId' does not exist on type 'Session & Partial<SessionData>'.ts(2339)
TypeScript
0 vote341 views1 answer
Typescript type specific numbers
TypeScript