Detailed explanation of PHP session session processing function examples-PHP Tutorial-php.cn

Home

Backend Development

PHP Tutorial

Detailed explanation of PHP session session processing function examples

墨辰丷

Jun 02, 2018 am 09:04 AM

phpsessionExample

This article mainly introduces the relevant information of PHP session session processing function. Friends who need it can refer to it

PHP Session variables

When you run an application, you open it, make changes, and then close it. It's a lot like a session. The computer knows who you are. It knows when you start the application and when it terminates it. But on the Internet, there's a problem: the server doesn't know who you are and what you do, and that's because HTTP addresses don't maintain state.

PHP session solves this problem by storing user information on the server for subsequent use (such as user name, purchased items, etc.). However, session information is temporary and will be deleted after the user leaves the site. If you need to store information permanently, you can store the data in a database.

Session works by creating a unique id (UID) for each visitor and storing variables based on this UID. The UID is stored in a cookie or passed through the URL.

1. Start a session

Before saving information to the session, you must first open the session. PHP provides the session_start() function to start or continue a session. Definition:

1 bool session_start( void )

Call as follows:

<?php session_start();?>
 <html>
 <body></body>
 </html>

Note:

(1) The session_start() function must be located before the tag, that is, the function must be called before any output. It is often done without paying attention when writing a program. A space or carriage return will result in an error. Special attention should be paid to this. (I have been tricked)

(2) Regardless of whether the session is successfully created or not, the session_start() function will return TRUE, so any exception handling will not work.

(3) You can also enable the configuration instruction session.auto_start, so that you do not have to execute this function, but in this case, each PHP page will start or continue a session when it is executed.

2. Store or read session

The correct way to store and read session variables is to use PHP's S ESSION variable. SESSION variable. _SESSION is a global parameter provided by PHP and is specially used to store and read sessions. (Note that the key names of associative arrays are consistent with the naming rules of ordinary variables)

When storing a session, you can assign it directly.

$_SESSION['season'] = 'Autumn';

The above sets a session element with the key name "season" and its value is "autumn" . When reading, it is just like calling a normal array element.

The following two code snippets show how to store and read a session element.

This is the session1.php file:

 <?php
 /**
  * Created by PhpStorm.
  * User: yuxiu
  * Date: //
  * Time: :
  */
 if(isset($_POST[&#39;submit&#39;])){
   session_start();                //开始建立一个会话
   $_SESSION[&#39;season&#39;] = $_POST[&#39;season&#39;];    //存储会话数据
   header("Location: session.php");      //应特别注意header()里的格式问题
 }
 ?>
 <b>存储会话</b>
 <hr/>
 选择需要设置的数据：
 <form name="form" method="post" action="" id="form" >
   <select name="season" id="season_select" >
     <option value="春天">春天</option>
     <option value="夏天">夏天</option>
     <option value="秋天">秋天</option>
     <option value="冬天">冬天</option>
   </select>
   <br/>
   <br/>
   <br/>
  <input type="submit" name="submit" value="submit"/>
 </form>

This is the session2.php file:

 <?php
 /**
  * Created by PhpStorm.
  * User: yuxiu
  * Date: //
  * Time: :
  */
 session_start();  //建立或者继续一个会话
 $season = $_SESSION[&#39;season&#39;];    //读取会话数据
 echo "<b>读取会话</b><br/><br/>";
 switch ($season) {
   case &#39;春天&#39;;
     echo &#39;现在是绿意盎然的春天！&#39;;
     break;
   case &#39;夏天&#39;;
     echo &#39;现在是热情四溢的夏天！&#39;;
     break;
   case &#39;秋天&#39;;
     echo &#39;现在是丰收果实的秋天!&#39;;
     break;
   case &#39;冬天&#39;;
     echo &#39;现在是白雪皑皑的冬天!&#39;;
     break;
   default ;
     echo &#39;对不起，会话中没有数据 或者 不存在该对话 ！&#39;;
 }
 ?>

In session1.php, first use session_start() to create a session, then use array assignment to store the submitted seasonal data, and finally use the header() function to jump directly to the beginning. In the session2.php file, the session_start() function is also needed to continue a session and use the session array to call session information.

3. Destroy the session

When the session is no longer in use, you need to destroy it manually, although PHP has the ability to automatically destroy the session function, but this will make the program less efficient. You can use the unset() function or session_destroy() function.

<?php
 unset($_SESSION[&#39;season&#39;]);
?>

Or:

<?php
 session_destroy();   //注意，使用这个函数将重置session数组，即失去所有的已经储存的session数据
?>

Summary: The above is the entire content of this article, I hope it will be helpful to everyone's study.

Related recommendations:

PHP realizes the function of randomly outputting domestic IP

php ajax implementation Method to register the real-time verification function

PHP Ajax implements the real-time verification function of the verification code

The above is the detailed content of Detailed explanation of PHP session session processing function examples. 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

SpringBoot Session怎么设置会话超时May 15, 2023 pm 02:37 PM

问题发现springboot项目生产session-out超时问题，描述下问题：在测试环境通过改动application.yaml配置session-out,经过设置不同时间验证session-out配置生效，于是就直接设置了过期时间为8小时发布到了生产环境。然而中午接到客户反应项目过期时间设置较短，半小时不操作就会话过期需要反复登陆。解决处理开发环境：springboot项目内置Tomcat，所以项目中application.yaml配置session-out是生效的。生产环境：生产环境发布是

php session刷新后没有了怎么办Jan 18, 2023 pm 01:39 PM

php session刷新后没有了的解决办法：1、通过“session_start();”开启session；2、把所有的公共配置写在一个php文件内；3、变量名不能和数组下标相同；4、在phpinfo里面查看session数据的存储路径，并查看该文件目录下的sessio是否保存成功即可。

session php默认失效时间是多少Nov 01, 2022 am 09:14 AM

session php默认失效时间是1440秒，也就是24分钟，表示客户端超过24分钟没有刷新，当前session就会失效；如果用户关闭了浏览器，会话就会结束，Session就不存在了。

Springboot2 session设置超时时间无效怎么解决May 22, 2023 pm 01:49 PM

问题：今天项目中遇到了一个设置时间超时的问题，按SpringBoot2的application.properties更改一直不生效。解决方案：server.*属性用于控制SpringBoot使用的嵌入式容器。SpringBoot将使用ServletWebServerFactory实例之一创建servlet容器的实例。这些类使用server.*属性来配置受控的servlet容器（tomcat，jetty等）。当应用程序作为war文件部署到Tomcat实例时，server.*属性不适用。它们不适用，

PHP如何在多个文件中正确地读取和写入Session数据Mar 23, 2023 am 11:12 AM

当您在使用PHP会话（Session）时，有时会发现Session在一个文件中可以正常读取，但在另一个文件中却无法读取。这可能会让您感到困惑，因为会话数据应该可以在整个应用程序中共享。本文将解释如何在多个文件中正确地读取和写入PHP会话数据。

Redis的共享session应用如何实现短信登录Jun 03, 2023 pm 03:11 PM

1.基于session实现短信登录1.1短信登录流程图1.2实现发送短信验证码前端请求说明：说明请求方式POST请求路径/user/code请求参数phone（电话号码）返回值无后端接口实现：@Slf4j@ServicepublicclassUserServiceImplextendsServiceImplimplementsIUserService{@OverridepublicResultsendCode(Stringphone,HttpSessionsession){//1.校验手机号if

JavaScript和PHP的cookie之间有哪些区别？Sep 02, 2023 pm 12:29 PM

JavaScriptCookie使用JavaScriptcookie是记住和跟踪偏好、购买、佣金和其他信息的最有效方法。更好的访问者体验或网站统计所需的信息。PHPCookieCookie是存储在客户端计算机上的文本文件并保留它们用于跟踪目的。PHP透明地支持HTTPcookie。JavaScriptcookie如何工作？您的服务器将一些数据发送到访问者的浏览器cookie的形式。浏览器可以接受cookie。如果存在，它将作为纯文本记录存储在访问者的硬盘上。现在，当访问者到达站点上的另一个页面时

PHP如何处理微信小程序中的session问题Jun 02, 2023 pm 03:40 PM

近年来，微信小程序风靡全球，已经成为了许多企业和个人开发者的首选平台。在小程序的开发中，我们经常会遇到session问题，也就是如何在小程序中保存用户登录状态。这个问题对于网站开发者来说并不陌生，但在小程序中却有些不同。本文将介绍如何使用PHP解决微信小程序中的session问题。一、小程序登录过程概述小程序的登录流程与网站的登录流程类似，分为以下几个步骤：

See all articles

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

AI Hentai Generator

Generate AI Hentai for free.

Hot Article

R.E.P.O. Energy Crystals Explained and What They Do (Yellow Crystal)

2 weeks agoBy尊渡假赌尊渡假赌尊渡假赌

Hello Kitty Island Adventure: How To Get Giant Seeds

1 months agoBy尊渡假赌尊渡假赌尊渡假赌

How Long Does It Take To Beat Split Fiction?

4 weeks agoByDDD

R.E.P.O. Save File Location: Where Is It & How to Protect It?

4 weeks agoByDDD

Two Point Museum: All Exhibits And Where To Find Them

1 months agoBy尊渡假赌尊渡假赌尊渡假赌

Hot Tools

EditPlus Chinese cracked version

Small size, syntax highlighting, does not support code prompt function

SublimeText3 Chinese version

Chinese version, very easy to use

DVWA

Damn Vulnerable Web App (DVWA) is a PHP/MySQL web application that is very vulnerable. Its main goals are to be an aid for security professionals to test their skills and tools in a legal environment, to help web developers better understand the process of securing web applications, and to help teachers/students teach/learn in a classroom environment Web application security. The goal of DVWA is to practice some of the most common web vulnerabilities through a simple and straightforward interface, with varying degrees of difficulty. Please note that this software