php中filter函数验证邮箱、url和ip地址的实例

function isEmail($email){
 if(preg_match("/^[0-9a-zA-Z]+@(([0-9a-zA-Z]+)[.])+[a-z]{2,4}$/i",$email )) {
     return '邮箱验证OK';
        } else {
 return '验证不是邮箱';
 }
}
?>

$email = '[email protected]'; 

$result = filter_var($email, FILTER_VALIDATE_EMAIL); 

var_dump($result); //string(14) "[email protected]"

$url = 'www.111com.net';
$search = '/---正则N---/';
if(preg_match($search,$url)){
 echo '匹配';
}else {
 echo '不匹配';
}
?>

$url = "http://www.111com.net"; 

$result = filter_var($url, FILTER_VALIDATE_URL); 

var_dump($result); //string(22) "http://www.111com.net"

/**
* 检查IP地址是否正确。
*/
function checkipaddres ($ipaddres) {
$preg="/A((([0-9]?[0-9])|(1[0-9]{2})|(2[0-4][0-9])|(25[0-5])).){3}(([0-9]?[0-9])|(1[0-9]{2})|(2[0-4][0-9])|(25[0-5]))Z/";
if(preg_match($preg,$ipaddres))return true;
return false;
}

$url = "192.168.1.110"; 

$result = filter_var($url, FILTER_VALIDATE_IP); 

var_dump($result); //string(13) "192.168.1.110"

$url = "2001:DB8:2de::e13"; 

$result = filter_var($url, FILTER_VALIDATE_IP); 

var_dump($result); //string(17) "2001:DB8:2de::e13"

$i = '010'; 

$result = filter_var( 

     $i, 

     FILTER_VALIDATE_INT, 

     //设定校验的数值范围 

     array( 

      'options' => array('min_range' => 1, 'max_range' => 100) 

     ) 

 ); 

var_dump($result);//bool(false)

 $i = '010'; 

$result = $i >= 1 && $i <= 100; 

 var_dump($result);//bool(true)

$float = 12.312; 

$result = filter_var($float, FILTER_VALIDATE_FLOAT); 

var_dump($result); //float(12.312)