How to log in and log out with PHP (example demonstration)
In the previous article "PHP uses 3 predefined variables to quickly obtain form data", we learned about 3 methods to quickly obtain form data. Friends in need can learn about it~
When we browse and operate a website, we often need to log in, so how do we log in as a user? When we finish browsing, what should we do if we want to log out (logout status)? Let me introduce it to you below.
This article will combine a detailed example to give you a detailed introduction to how to use PHP to log in users, set up a successful login session, and log out the login status.
First look at How to perform user login:
First we create a login form (login.html), which contains a text field named username, a name It is a password text field and a submit button, and we set the method to post, and the submitted data is handed over to login.php for processing.
The form is as follows:
<!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>用户登录</title> </head> <body> <form action="login.php" method="post"> 用户名: <input type="text" name="username"> <br><br> 密 码: <input type="password" name="password"> <br><br> <input type="submit" name="submit"value="登录"> </form> </body> </html>
Then create another page "login.php" to perform the login operation:
First confirm that if the user logs in, it must be a POST action submission . Then check whether the information entered by the user is correct. If it is correct, register the session information. Otherwise, it will prompt that the login failed and the user needs to try again.
The code is as follows:
<?php
header("content-type:text/html;charset=utf-8");
session_start(); //开启session会话
//登录
if(!isset($_POST['submit'])){
exit('非法访问!');
}
//获取用户名和密码
$username=$_POST['username'];
$password=$_POST['password'];
//检测用户名及密码是否正确
if($username=="李华"){
if($password=="123456"){
//登录成功
$_SESSION['username'] = $username;
echo $_SESSION['username'],' 欢迎你！进入 <a href="#">用户中心</a><br />';
echo '点击此处 <a href="logout.php?action=logout">注销</a> 登录！<br />';
exit;
}else{
echo "密码错误";
}
}else{
echo "用户名不存在";
}
?>
Then let’s see how to log out:
When the user logs out , you need to delete the SESSION and delete the information saved in the session.
Processing steps: When the user clicks the "Logout" button, the logout.php page is entered and the information in the session is deleted.
//注销登录
if($_GET['action'] == "logout"){
unset($_SESSION['username']);
echo '注销登录成功！点击此处 <a href="login.html">登录</a>';
exit;
} "162986981591757How to log in and log out with PHP (example demonstration)")
Finally, I would like to recommend the latest and most comprehensive "PHP Video Tutorial"~ Come and learn!
The above is the detailed content of How to log in and log out with PHP (example demonstration). For more information, please follow other related articles on the PHP Chinese website!
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
1657
14
1415
52
1309
25
1257
29
1230
24
How do you parse and process HTML/XML in PHP?
Feb 07, 2025 am 11:57 AM
This tutorial demonstrates how to efficiently process XML documents using PHP. XML (eXtensible Markup Language) is a versatile text-based markup language designed for both human readability and machine parsing. It's commonly used for data storage an
Explain JSON Web Tokens (JWT) and their use case in PHP APIs.
Apr 05, 2025 am 12:04 AM
JWT is an open standard based on JSON, used to securely transmit information between parties, mainly for identity authentication and information exchange. 1. JWT consists of three parts: Header, Payload and Signature. 2. The working principle of JWT includes three steps: generating JWT, verifying JWT and parsing Payload. 3. When using JWT for authentication in PHP, JWT can be generated and verified, and user role and permission information can be included in advanced usage. 4. Common errors include signature verification failure, token expiration, and payload oversized. Debugging skills include using debugging tools and logging. 5. Performance optimization and best practices include using appropriate signature algorithms, setting validity periods reasonably,
Explain late static binding in PHP (static::).
Apr 03, 2025 am 12:04 AM
Static binding (static::) implements late static binding (LSB) in PHP, allowing calling classes to be referenced in static contexts rather than defining classes. 1) The parsing process is performed at runtime, 2) Look up the call class in the inheritance relationship, 3) It may bring performance overhead.
PHP Program to Count Vowels in a String
Feb 07, 2025 pm 12:12 PM
A string is a sequence of characters, including letters, numbers, and symbols. This tutorial will learn how to calculate the number of vowels in a given string in PHP using different methods. The vowels in English are a, e, i, o, u, and they can be uppercase or lowercase. What is a vowel? Vowels are alphabetic characters that represent a specific pronunciation. There are five vowels in English, including uppercase and lowercase: a, e, i, o, u Example 1 Input: String = "Tutorialspoint" Output: 6 explain The vowels in the string "Tutorialspoint" are u, o, i, a, o, i. There are 6 yuan in total
What are PHP magic methods (__construct, __destruct, __call, __get, __set, etc.) and provide use cases?
Apr 03, 2025 am 12:03 AM
What are the magic methods of PHP? PHP's magic methods include: 1.\_\_construct, used to initialize objects; 2.\_\_destruct, used to clean up resources; 3.\_\_call, handle non-existent method calls; 4.\_\_get, implement dynamic attribute access; 5.\_\_set, implement dynamic attribute settings. These methods are automatically called in certain situations, improving code flexibility and efficiency.
PHP and Python: Comparing Two Popular Programming Languages
Apr 14, 2025 am 12:13 AM
PHP and Python each have their own advantages, and choose according to project requirements. 1.PHP is suitable for web development, especially for rapid development and maintenance of websites. 2. Python is suitable for data science, machine learning and artificial intelligence, with concise syntax and suitable for beginners.
PHP: A Key Language for Web Development
Apr 13, 2025 am 12:08 AM
PHP is a scripting language widely used on the server side, especially suitable for web development. 1.PHP can embed HTML, process HTTP requests and responses, and supports a variety of databases. 2.PHP is used to generate dynamic web content, process form data, access databases, etc., with strong community support and open source resources. 3. PHP is an interpreted language, and the execution process includes lexical analysis, grammatical analysis, compilation and execution. 4.PHP can be combined with MySQL for advanced applications such as user registration systems. 5. When debugging PHP, you can use functions such as error_reporting() and var_dump(). 6. Optimize PHP code to use caching mechanisms, optimize database queries and use built-in functions. 7
PHP in Action: Real-World Examples and Applications
Apr 14, 2025 am 12:19 AM
PHP is widely used in e-commerce, content management systems and API development. 1) E-commerce: used for shopping cart function and payment processing. 2) Content management system: used for dynamic content generation and user management. 3) API development: used for RESTful API development and API security. Through performance optimization and best practices, the efficiency and maintainability of PHP applications are improved.
