UPPEValidator is a simple PHP class that will help validate email addresses, URLs, passwords, and phone numbers.

UPPEValidator.php

<?php
/********************************************************************************************/
/* UPPEValidator created by Angelo Villegas [http://www.studiovillegas.com]					*/
/*																							*/
/* Copyright © Angelo Villegas																*/
/* Permission is hereby granted, free of charge, to any person obtaining a copy of this		*/
/* software and associated documentation files (the "Software"), to deal in the Software	*/
/* without restriction, including without limitation the rights to use, copy, modify,		*/
/* merge, publish, distribute, sublicense, and/or sell copies of the Software, and to		*/
/* permit persons to whom the Software is furnished to do so, subject to the following		*/
/* conditions:																				*/
/*																							*/
/* The above copyright notice and this permission notice shall be included in all copies	*/
/* or substantial portions of the Software.													*/
/*																							*/
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,		*/
/* INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A			*/
/* PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT		*/
/* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF		*/
/* CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE		*/
/* OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.											*/
/********************************************************************************************/

class UPPEValidator
{
	function is_email( $string )
	{
		$bool = ( preg_match( '/^([.0-9a-z_-]+)@(([0-9a-z-]+\.)+[0-9a-z]{2,4})$/i' , $string ) ) ? true : false;
		
		return $bool;
	}
	
	function is_url_string( $string )
	{
		$bool = ( preg_match( '@(https?://([-\w\.]+)+(:\d+)?(/([\w/_\.]*(\?\S+)?)?)?)@' , $string ) ) ? true : false;
		
		return $bool;
	}
	
	function is_password( $string )
	{
		$bool = ( preg_match( '/^(?=.*\d)(?=.*[a-z])(?=.*[A-Z]).{6,18}$/i' , $string ) ) ? true : false;
		
		return $bool;
	}
	
	function is_phone( $string )
	{
		$bool = ( preg_match( '/^([.\-0-9]+)$/i' , $string ) ) ? true : false;
		
		return $bool;
	}
}
?>