php 验证邮箱、url、数字程序代码

public static function isEmail( $email )

{

return preg_match("/^([a-z0-9]*[-_＼.]?[a-z0-9]+)*@([a-z0-9]*[-_]?[a-z0-9]+)+[＼.][a-z]{2,4}([＼.][a-z]{2})?$/i" , $email  );
}

public static function isNumber( $num )
{
return is_numeric( $num );
}

public static function isUrl( $url , $preg = false )
{
if( $preg )
{
$status = preg_match ( "/^([^:＼/＼/])+＼:＼/＼/[＼w-]+＼.[＼w-.＼?＼/]+$/" , $url );
}
else
{
$status =  filter_var( $url , FILTER_VALIDATE_URL );
}

return $status;
}

$email = 'fengdingbo@gmail.com';                                               
$result = filter_var($email, FILTER_VALIDATE_EMAIL);
var_dump($result); // string(20) "fengdingbo@gmail.com"

$url = "http://www.111cn.net";
$result = filter_var($url, FILTER_VALIDATE_URL);
var_dump($result); // string(25) "http://www.111cn.net"

$url = "192.168.1.110";                                                        
$result = filter_var($url, FILTER_VALIDATE_IP);
var_dump($result); // string(13) "192.168.1.110"
// 该方法也可以用来验证ipv6。
$url = "2001:DB8:2de::e13";                                                    
$result = filter_var($url, FILTER_VALIDATE_IP);
var_dump($result); // string(17) "2001:DB8:2de::e13"