How i can create a Typescript interface that can take also a string?

Question

I need to create an interface that permit to have an array of objects and strings.

For example:

const array = [
 '',
 {id: '', labels: ['']}
]

I've tried with:

export interface Obj{
  id: string;
  label: string[];
}

export interface Objs extends Array<Obj> {
}

But this don't permit strings so this return an error:

const array: Objs = [
 '',
 {id: '', labels: ['']}
]

user2369797 · Accepted Answer · 2020-05-08 11:14:20Z

2

You have to use union types:

export type Objs = Array<Obj | string>;

answered May 8, 2020 at 11:14

user2369797

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Comments

T.J. Crowder · Accepted Answer · 2020-05-08 11:12:14Z

1

If the entries in the array can be either strings or objects in the form {id: string; labels: string[]}, you can use a union type:

export type Obj = string | {id: string; labels: string[]};
const array: Obj[] = [
    "",
    {id: "", labels: [""]}
];

answered May 8, 2020 at 11:12

T.J. Crowder

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