export declare class StringUtil {
    static capitalize(str: string): string;
    static toCamelCase(str: string): string;
    static toSnakeCase(str: string): string;
    static toKebabCase(str: string): string;
    static truncate(str: string, length: number, suffix?: string): string;
    static slugify(str: string): string;
    static generateSlug(str: string, maxLength?: number): string;
    static maskEmail(email: string): string;
    static maskPhone(phone: string): string;
    static removeSpecialCharacters(str: string): string;
    static removeExtraSpaces(str: string): string;
    static isPalindrome(str: string): boolean;
    static countWords(str: string): number;
    static countCharacters(str: string, includeSpaces?: boolean): number;
}