/**
 * @description: 获取设备的型号
 * @param {string} userAgent window.userAgent
 * @return {string} mobile/ipad/pc
 */
export declare function getDevice(userAgent?: string): Device;
/**
 * @description: 是否为手机
 * @return {boolean}
 */
export declare function isMobile(): boolean;
/**
 * @description: 判断屏幕最大宽度不超过
 * @param {number} width 要判断的最大宽度
 * @return {boolean} 屏幕宽度是否小于等于 width
 */
export declare function screenMaxIs(width: number): boolean;
/**
 * @description: 判断是否为 number 类型
 * @param {any} attr
 * @return {boolean}
 */
export declare function isNumber(attr: any): attr is number;
/**
 * @description: 判断是否为 string 类型
 * @param {any} attr
 * @return {boolean}
 */
export declare function isString(attr: any): attr is string;
export type Device = 'mobile' | 'ipad' | 'pc';