Here is the updated version for `activeEmails` function using array methods:

```ts
export interface User {
  email: string;
  active: boolean;   
} 

/** The lowercased addresses of the active users, in order. */
export function activeEmails(users: readonly User[]): string[] {
  return users
    .filter((user) => user.active )
    .map((user) => user.email.toLowerCase()); 
}                   
```