export function capitalize(str: string): string;
export function reverse(str: string): string;
export function isPalindrome(str: string): boolean;
export function kebabCase(str: string): string;
export function camelCase(str: string): string;
export function unique<T>(arr: T[]): T[];
export function flatten(arr: any[]): any[];
export function last<T>(arr: T[]): T | undefined;
export function add(a: number, b: number): number;
export function clamp(num: number, min: number, max: number): number;
export function randomInt(min: number, max: number): number;
export function sum(arr: number[]): number;
export function average(arr: number[]): number;
export function round(num: number, decimals?: number): number;
export function factorial(n: number): number;
export function gcd(a: number, b: number): number;
export function lcm(a: number, b: number): number;
export function formatDate(date: Date): string;
export function daysBetween(date1: Date, date2: Date): number;
export function now(): Date;
export function formatTime(date: Date): string;
export function addDays(date: Date, days: number): Date | null;
export function isLeapYear(year: number): boolean;
export function isEmpty(obj: object): boolean;
export function deepClone<T>(obj: T): T;
export function deepEqual(a: any, b: any): boolean;
export function get(obj: any, path: string, defaultValue?: any): any;
export function merge<T, U>(obj1: T, obj2: U): T & U;
export function debounce<F extends (...args: any[]) => any>(fn: F, delay: number): F;
export function throttle<F extends (...args: any[]) => any>(fn: F, limit: number): F;
export function once<F extends (...args: any[]) => any>(fn: F): F;
export function isArray(val: any): val is any[];
export function isObject(val: any): boolean;
export function isString(val: any): val is string;
export function isNumber(val: any): val is number;
export function isFunction(val: any): val is Function;
export function isDate(val: any): val is Date;
export function isBoolean(val: any): val is boolean;
export function isNull(val: any): val is null;
export function isUndefined(val: any): val is undefined;
export function getQueryParam(url: string, key: string): string | null;
export function parseJSON(str: string, fallback?: any): any;
export function encodeQuery(obj: Record<string, string | number | boolean>): string;
export function decodeQuery(query: string): Record<string, string>;
export function formatNumber(num: number, locales?: string): string;
export function pad(num: number, size?: number): string;
export function hello(): string;

export function uuid(): string;
export function sha256(str: string): string;
export function readFile(path: string): string;
export function writeFile(path: string, data: string): void;
export function isEmail(str: string): boolean;
export function isAlpha(str: string): boolean;
export function isUUID(str: string): boolean;
export function randomElement<T>(arr: T[]): T;
export function randomInt(min:number,max:number): number;
export function randomBoolean(): boolean;
export function isNode(): boolean;
export function isBrowser(): boolean;
export function formatBytes(bytes:number):string;
export function formatPercentage(num:number,decimals?:number):string;
export function now():number;
export function measureSync(fn:()=>void):number;
export function mean(arr:number[]):number;
export function median(arr:number[]):number;
export function mode(arr:number[]):any[];
export function snakeCase(str:string):string;
export function kebabCase(str:string):string;
export function pascalCase(str:string):string;
export function hexToRgb(hex:string):number[];
export function rgbToHex(r:number,g:number,b:number):string;
export function daysBetween(a:Date,b:Date):number;
export function addDays(d:Date,n:number):Date;
export function isLeapYear(y:number):boolean;
export function isMobile():boolean;
export function getBrowser():string;
export function chunk<T>(arr:T[],size:number):T[][];
export function compact<T>(arr:T[]):T[];
export function flatten(arr:any[]):any[];
export function keys(obj:any):string[];
export function values(obj:any):any[];
export function entries(obj:any):[string,any][];
export function delay(ms:number):Promise<void>;
export function timeout<T>(p:Promise<T>,ms:number):Promise<T>;
export function uuid():string;
export function sha256(str:string):string;
export function readFile(path:string):string;
export function writeFile(path:string,data:string):void;
export function getQueryParam(url:string,key:string):string|null;
export function encodeQuery(obj:Record<string,string|number|boolean>):string;