# TypeScript type for a string or array of strings

> Learn how to declare a TypeScript type that can be either a string or an array of strings using a union, written as string or string[].

Author: Flavio Copes | Published: 2023-12-21 | Canonical: https://flaviocopes.com/typescript-declare-a-type-that-can-be-a-string-or-array-of-strings/

Simple one, but I forgot the exact syntax and had to search for it, so let me write it:

```typescript
export interface Props {
  tag: string | string[]
}
```

`tag` can be a string, or an array of strings