/**
 * Check if value is a valid DDD.
 * @example ```js
 * isDDD('81')
 * //=> true
 *
 * isDDD('10')
 * //=> false
 *
 * isDDD('A#')
 * //=> false
 * ```
 * @param code
 */
declare const isDDD: (code: string) => boolean;
export default isDDD;