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

3 votes178 views1 answer
Sort list of lists by first element
TypeScript
1 vote186 views1 answer
Window typescript
TypeScript
0 vote204 views1 answer
Delete attachments in nodejs
TypeScript
5 votes186 views3 answers
Typescript check type
TypeScript
17 votes206 views4 answers
Pygame mouse events
TypeScript
3 votes187 views3 answers
Import images angular
TypeScript
1 vote166 views1 answer
Firefox hsts clear
TypeScript
5 votes175 views1 answer
Git remove commits from branch after push
TypeScript
0 vote190 views1 answer
SetTimeout without arguments
TypeScript
0 vote175 views1 answer
Custom validation for phone-number using class-validator package
TypeScript