The filter function in php verifies the mailbox, url, and IP address instance.

Source: Internet
Author: User
Tags preg
Before reading this function, I verified that the mailbox, IP address, and url are all processed using regular expressions. today, I found that the filter function can replace regular expressions and the method is simple and easy to use, the following example describes how to use this function. I didn't know filt when I used php in my early years... before reading this function, I verified that the mailbox, IP address, and url are all processed using regular expressions. today, I found that the filter function can replace regular expressions and the method is simple and easy to use, the following example describes how to use this function.

When I was using php in the early years, I still didn't know the filter feature. at that time, I used regular expressions to determine whether the mailbox, url, and IP address format were correct. later, as I went deeper, in php, you can also use the built-in function library filter to complete these functions.

1. verify emailFirst, let's look at the original regular expression verification. the code is as follows:

 

Let's look at the filter code as follows:

$email = 'sjlinyu@qq.com';  $result = filter_var($email, FILTER_VALIDATE_EMAIL);  var_dump($result); //string(14) "sjlinyu@qq.com"

For the filter_var function, if the verification succeeds, the verification object is returned; otherwise, false is returned, which makes the latter simpler.

2. verify the url address and regular expression. the code is as follows:

  

The code of the filter_var function is as follows:

$url = "http://www.phprm.com";  $result = filter_var($url, FILTER_VALIDATE_URL);  var_dump($result); //string(22) "http://www.phprm.com"

3. verify the IP address and the regular expression function. the code is as follows:

/*** Check whether the IP address is correct. */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 ;}

The code for this function verification is as follows:

$url = "192.168.1.110";  $result = filter_var($url, FILTER_VALIDATE_IP);  var_dump($result); //string(13) "192.168.1.110"

This method can also be used to verify ipv6. the code is as follows:

$url = "2001:DB8:2de::e13";  $result = filter_var($url, FILTER_VALIDATE_IP);  var_dump($result); //string(17) "2001:DB8:2de::e13"

4. check whether the value is an integer within an integer range. the code is as follows:

$ I = '010 '; $ result = filter_var ($ I, FILTER_VALIDATE_INT, // set the value range of the check value array ('options' => array ('min _ range' => 1, 'max _ range' => 100 ))); var_dump ($ result); // bool (false)

Php variables are of a weak type. If a filter is not used, it is true to use a variable greater than or less than the symbol. the code is as follows:

$i = '010';  $result = $i >= 1 && $i <= 100;  var_dump($result);//bool(true)

5. verify the floating point. The code is as follows:

$float = 12.312;  $result = filter_var($float, FILTER_VALIDATE_FLOAT);  var_dump($result); //float(12.312)

When verifying the amount, you often need to verify whether the amount is a floating point number.

Summary: Although the filter in php is relatively unpopular, it is quite powerful. in addition to the above functions, there are also some filtering input functions. you can refer to the php Manual.


Link to this article:

Add to favorites ^ please keep the tutorial address.

Related Article

Contact Us

The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

If you find any instances of plagiarism from the community, please send an email to: info-contact@alibabacloud.com and provide relevant evidence. A staff member will contact you within 5 working days.

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

  • Sales Support

    1 on 1 presale consultation

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.