search
HomeBackend DevelopmentPHP ProblemHow to use PHP regular expression to validate form data? (detailed steps)

The previous article introduced to you "How to use regular replacement to clear all HTML tags in a string? 》, this article continues to introduce to you how to use PHP regular expressions to verify form data?

How to use PHP regular expression to validate form data? (detailed steps)

#How to use PHP regular expressions to validate form data?

First, we lay out our HTML form, and then add the form tag (note: all user-related content must be transmitted using post), and then, we Add the account number, password and email address to the form, and finally add a login button.

Take the code demonstration as an example:

<?php 
/*******用户数据验证*********/
?>
<!DOCTYPE html>
<html>
<head>
      <meta charset="UTF-8">
      <title>用户信息验证</title>
</head>
<body>
      <form action="" method=" post">
          账号:
      <input type="text" name="name" value="" /><br/>
          密码:<!--密码一定用type=password
          这里没用的原因是为了让大家看到输入的内容-->
      <input type= "text" name="pwd" value="" /><br/> 
          邮箱:
      <input type= "text" name=" email" value="" /><br/>
      <input type="submit" value="登录" >
 </form>

The code results are as follows;

How to use PHP regular expression to validate form data? (detailed steps)

The operation result is successful, but the case we gave shows that the account number needs to be composed of letters, numbers and underscores. The password needs to be composed of 8-16 characters of uppercase and lowercase letters and numbers. The email address needs to enter the correct email address. Therefore, we add rules that need to be added by default in the code. The code demonstration is as follows;

<?php 
/*******用户数据验证*********/
    $userInfo = &#39;字母数字以及下划线组成&#39;;
    $pwdInfo = &#39;6-13位大小写字母以及数字&#39;;
    $emailInfo = &#39;输入正确的email地址&#39; ;
?>
<!DOCTYPE html>
<html>
<head>
      <meta charset="UTF-8">
      <title>用户信息验证</title>
</head>
<body>
      <form action="" method=" post">
          账号:
      <input type="text" name="name" value="" /><?=$userInfo?><br/>
          密码:<!--密码一定用type=password
          这里没用的原因是为了让大家看到输入的内容-->
      <input type= "text" name="pwd" value="" /><?=$pwdInfo?><br/> 
          邮箱:
      <input type= "text" name=" email" value="" /><?=$emailInfo?><br/>
      <input type="submit" value="登录" >
 </form>

The code results are as follows As shown;

How to use PHP regular expression to validate form data? (detailed steps)

According to the code display, the content we need is also displayed in the running results, but after we get the default display, we need to define the verification rules. Verification Whether the content output by the user meets the requirements; for example, we take the user as an example, first define $userpattern = '/^\w $/S'; and then make a judgment and add an if conditional sentence. In the if statement, if it is not set The user will not be able to judge the conditional sentence, or will not enter if the setting is wrong, and so on. Let’s take the code as an example:

<?php 
/*******用户数据验证*********/
    $userInfo = &#39;字母数字以及下划线组成&#39;;
    $pwdInfo = &#39;6-13位大小写字母以及数字&#39;;
    $emailInfo = &#39;输入正确的email地址&#39; ;
    $userPattern =&#39;/^\w+$/S&#39;;
    if(isset($_POST[&#39;name&#39;])){
    if(preg_match($userPattern,$_POST[&#39;name&#39;])){
        $userInfo = &#39;<font color="green">正确</font>&#39;;
    }else{
        $userInfo = &#39;<fort color= "pick">字母数字以及下划线组成</font>&#39;;
    }
     $pwdPattern =&#39;/^[a-zA-Z0-9]{6,13}$/S&#39;;
     if(isset($_POST[&#39;pwd&#39;])){
         if(preg_match($pwdPattern,$_POST[&#39;pwd&#39;])){
     $pwdInfo =&#39;<font color=" green">正确</font>&#39;;
     }else{
        $pwdInfo = &#39;<fort color= "pick">6-13位大小写字母以及数字</font>&#39;;
     }
    }
    $emailPattern = &#39;/^\w+@[0-9a-zA-Z]+(\.[a-zA-Z]{2,5})+$/S&#39;;
   if(isset($_POST[&#39;email&#39;])){
   if (preg_match( $emailPattern,$_POST[&#39;email&#39;])){
   $emailInfo = &#39;<font color=" green">正确</font>&#39; ;
   }else{
   $emailInfo = &#39;<font color="red" >输入正确的email地址</font>&#39;;
}
}
?>

The code results are as follows;

How to use PHP regular expression to validate form data? (detailed steps)

Recommended learning: "PHP Video Tutorial"

The above is the detailed content of How to use PHP regular expression to validate form data? (detailed steps). For more information, please follow other related articles on the PHP Chinese website!

Statement
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
ACID vs BASE Database: Differences and when to use each.ACID vs BASE Database: Differences and when to use each.Mar 26, 2025 pm 04:19 PM

The article compares ACID and BASE database models, detailing their characteristics and appropriate use cases. ACID prioritizes data integrity and consistency, suitable for financial and e-commerce applications, while BASE focuses on availability and

PHP Secure File Uploads: Preventing file-related vulnerabilities.PHP Secure File Uploads: Preventing file-related vulnerabilities.Mar 26, 2025 pm 04:18 PM

The article discusses securing PHP file uploads to prevent vulnerabilities like code injection. It focuses on file type validation, secure storage, and error handling to enhance application security.

PHP Input Validation: Best practices.PHP Input Validation: Best practices.Mar 26, 2025 pm 04:17 PM

Article discusses best practices for PHP input validation to enhance security, focusing on techniques like using built-in functions, whitelist approach, and server-side validation.

PHP API Rate Limiting: Implementation strategies.PHP API Rate Limiting: Implementation strategies.Mar 26, 2025 pm 04:16 PM

The article discusses strategies for implementing API rate limiting in PHP, including algorithms like Token Bucket and Leaky Bucket, and using libraries like symfony/rate-limiter. It also covers monitoring, dynamically adjusting rate limits, and hand

PHP Password Hashing: password_hash and password_verify.PHP Password Hashing: password_hash and password_verify.Mar 26, 2025 pm 04:15 PM

The article discusses the benefits of using password_hash and password_verify in PHP for securing passwords. The main argument is that these functions enhance password protection through automatic salt generation, strong hashing algorithms, and secur

OWASP Top 10 PHP: Describe and mitigate common vulnerabilities.OWASP Top 10 PHP: Describe and mitigate common vulnerabilities.Mar 26, 2025 pm 04:13 PM

The article discusses OWASP Top 10 vulnerabilities in PHP and mitigation strategies. Key issues include injection, broken authentication, and XSS, with recommended tools for monitoring and securing PHP applications.

PHP XSS Prevention: How to protect against XSS.PHP XSS Prevention: How to protect against XSS.Mar 26, 2025 pm 04:12 PM

The article discusses strategies to prevent XSS attacks in PHP, focusing on input sanitization, output encoding, and using security-enhancing libraries and frameworks.

PHP Interface vs Abstract Class: When to use each.PHP Interface vs Abstract Class: When to use each.Mar 26, 2025 pm 04:11 PM

The article discusses the use of interfaces and abstract classes in PHP, focusing on when to use each. Interfaces define a contract without implementation, suitable for unrelated classes and multiple inheritance. Abstract classes provide common funct

See all articles

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

SublimeText3 Linux new version

SublimeText3 Linux new version

SublimeText3 Linux latest version

Dreamweaver Mac version

Dreamweaver Mac version

Visual web development tools

ZendStudio 13.5.1 Mac

ZendStudio 13.5.1 Mac

Powerful PHP integrated development environment

SecLists

SecLists

SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)