/**
 * 将undefined值变为'undefined'
 * @param data 数组或对象
 * @returns
 */
export declare function convertUndefinedToString(data: Recordable | any[]): void;
/**
 * 将'undefined'字符串还原为undefined
 */
export declare function revertUndefinedString(data: Recordable | any[]): void;
