/**
 * Class for validating strings.
 */
export declare class StringValidator {
    private readonly value;
    private isValid;
    /**
     * Creates a new StringValidator instance.
     * @param {any} value - The value to be validated.
     */
    constructor(value: any);
    /**
     * Checks if the value is of type string.
     * @returns {this} - The StringValidator instance.
     */
    isString(): this;
    /**
     * Checks if the string size is less than or equal to a maximum.
     * @param {number} maxSize - The maximum value allowed.
     * @returns {this} - The StringValidator instance.
     */
    isMaxSize(maxSize: number): this;
    /**
     * Checks if the string size is greater than or equal to a minimum.
     * @param {number} minSize - The minimum value allowed.
     * @returns {this} - The StringValidator instance.
     */
    isMinSize(minSize: number): this;
    /**
     * Checks if the string is a valid email address.
     * @returns {this} - The StringValidator instance.
     */
    isEmail(): this;
    /**
     * Checks if the string contains only alphanumeric characters.
     * @returns {this} - The StringValidator instance.
     */
    isAlphanumeric(): this;
    /**
     * Returns the result of the validation.
     * @returns {boolean} - The result of the validation.
     */
    getResult(): boolean;
}