/**
 * random a number.
 * @param min
 * @param max
 * @param fixed
 * @returns {*}
 */
export declare function randomFloat(min: number, max: number, fixed?: number): number;
/**
 * random boolean.
 * @returns {boolean}
 */
export declare function randomBool(): boolean;
/**
 * random a char.
 * @returns {*}
 */
export declare function randomChar(): string;
/**
 * random a string.
 * @param len
 * @returns {string}
 */
export declare function randomString(len: number): string;