Defining array with multiple types in TypeScript

I have an array of the form: [ 1, "message" ].

How would I define this in TypeScript?

Defining array with multiple types in TypeScript

Use a union type (string|number)[] demo:

const foo: (string|number)[] = [ 1, "message" ];

I have an array of the form: [ 1, "message" ].

If you are sure that there are always only two elements [number, string] then you can declare it as a tuple:

const foo: [number, string] = [ 1, "message" ];

And you can even provide meaningful names for the tuple members e.g. id and text:

const foo: [id: number, text: string] = [ 1, "message" ];

Stack Overflow Q#29382389, score: 855