How to create a type of array values?-CodePudding

I want to create a type that only accepts a specific combination of array values regardless of their order.

For example:

const acceptedCombo = ['a', 'b'];

function foo(param: MyType) {}

// Possible combos:
['a', 'b'] // OK
['b', 'a'] // OK
['a', 'b', 'c'] // TypeError - "c" is extra
['a'] // TypeError - "b" is missing

How can I define MyType?

CodePudding user response：

You can do it by this way:

type MyType = [string, string];

CodePudding user response：

Here's the type which you can define:

type Type = [string, string]

const v1: Type = ['a', 'b'] // OK
const v2: Type = ['b', 'a'] // OK
const v3: Type = ['a', 'b', 'c'] // Type '[string, string, string]' is not assignable to type 'Type'
const v4: Type = ['a'] // Type '[string]' is not assignable to type 'Type'.

Playground