export declare function GetNumber(value: any, defaultValue?: number): number;
export declare function IsNull(value: unknown): boolean;
export declare function IsNotNull(value: unknown): boolean;
/**
* Returns age as a human-readable string in years, months, weeks and days.
* E.g. "10 years, 5 months, 1 week, 2 days".
* If DOB is in the future or invalid, returns "0 days".
*
* @param DOB           Date or parsable date-string of birth
* @param referenceDate Date to calculate age against (default: now)
*/
export declare function GetAgeString(DOB: Date | string, referenceDate?: Date): string;