export declare function formatString(input: string): string;
/**
 * Converts a string to Title Case.
 *
 * Examples:
 *  - "APPROVE"         => "Approve"
 *  - "PENDING_REVIEW"  => "Pending Review"
 *  - "in_progress"     => "In Progress"
 *  - "DRAFT INVOICE"   => "Draft Invoice"
 *
 * @param {string} input - The string to convert.
 * @returns {string} - The string in Title Case.
 */
export declare function toTitleCase(input: string): string;
/**
 * Converts a camelCase or PascalCase string into a human-readable
 * title-cased string with spaces.
 *
 * This is useful for generating user-friendly field names in
 * validation or error messages.
 *
 * @example
 * camelCaseToTitle("noteDocument");
 * // → "Note Document"
 *
 * @example
 * camelCaseToTitle("additionalDocuments");
 * // → "Additional Documents"
 *
 * @example
 * camelCaseToTitle("PDFDocument");
 * // → "PDF Document"
 *
 * @param input - The camelCase or PascalCase string to convert
 * @returns A title-cased, space-separated string
 */
export declare function camelCaseToTitle(input: string): string;
/**
 * Capitalizes the first character of a string.
 *
 * @param str - The string to capitalize
 * @returns The string with its first character uppercased
 *
 * @example
 * capitalizeFirstWord('basicAmount') // 'BasicAmount'
 * capitalizeFirstWord('totalNetAmount') // 'TotalNetAmount'
 * capitalizeFirstWord('') // ''
 */
export declare function capitalizeFirstWord(str: string): string;