How to register and read Session in php
Register Session
Using Session Variables in php, in addition to starting, you also need to go through a registration The process of registering and reading Session variables must be completed by accessing the $_SESSION array. Starting from PHP 4.1.0 version, $_SESSION becomes a super global array like $_POST, $_GET and $_COOKIE, etc., but it can only be used after calling session_start() Function to open the Session. Unlike $HTTP_SESSION_VARS, $_SESSION always has global scope, so do not use the global keyword with $_SESSION. Key names in the $_SESSION associative array have the same naming rules as ordinary variable names in PHP.
After session variables are created, they are all stored in the array $_SESSION. Creating a session variable from the array $_SESSION is easy, just add an element directly to the array.
For example, the following example will start the session, create a Session variable and assign it a null value. The code is as follows:
<?php session_start(); // 启动 Session $_SESSION['name'] = null; // 声明一个名为 admin 的变量，并设置为空值 null。 ?>
After executing the script, the Session variable will be saved somewhere on the server side. in a folder. The location of the file is changed through the php.ini file. In the directory specified by the session.save_path attribute, a separate file is created for this access user to save the registered Session variables. For example, the name of a file that saves Session variables is in the form of "sess_09403850rf7sk39s67". The file name contains the Session ID, so each access user has his own file that saves Session variables in the server, and this file can be directly Use a text editor to open. The content structure of the file is as follows:
Variable name | Type: Length: Value //The same structure applies to each variable to save
As mentioned above, let’s give a simple example:
<?php //启动 session session_start(); //注册 session 变量，赋值为一个用户名称 $_SESSION['usermane'] = "sky"; //注册 session 变量，赋值为一个用户id $_SESSION['uid'] = 1; ?>
In the above example, Session has registered two variables. If a file that saves Session variables for this user is found in the server, , after opening, you can see the following content:
username | s:6: "sky"; uid | i:1:"1"; The contents of the two variables
Read the Session
First you need to determine the session variables Whether a session ID exists, if not, create one and make it accessible through the global array $_SESSION; if it already exists, load the created session variable for use by the user. For example: Determine whether the Session variable storing the user name is empty. If not, assign the session variable to $my_value.
The code is shown as follows:
<?php
if(!empty($_SESSION['session_name'])){ //判断存储用户名的 Session 会话变量是否为空
$my_value = $_SESSION['session_name']; //将会话变量赋予一个变量 $my_value
}
?>The above is the detailed content of How to register and read Session in php. 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
AI Hentai Generator
Generate AI Hentai for free.
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
1378
52
PHP 8.4 Installation and Upgrade guide for Ubuntu and Debian
Dec 24, 2024 pm 04:42 PM
PHP 8.4 brings several new features, security improvements, and performance improvements with healthy amounts of feature deprecations and removals. This guide explains how to install PHP 8.4 or upgrade to PHP 8.4 on Ubuntu, Debian, or their derivati
How To Set Up Visual Studio Code (VS Code) for PHP Development
Dec 20, 2024 am 11:31 AM
Visual Studio Code, also known as VS Code, is a free source code editor — or integrated development environment (IDE) — available for all major operating systems. With a large collection of extensions for many programming languages, VS Code can be c
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
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
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,
7 PHP Functions I Regret I Didn't Know Before
Nov 13, 2024 am 09:42 AM
If you are an experienced PHP developer, you might have the feeling that you’ve been there and done that already.You have developed a significant number of applications, debugged millions of lines of code, and tweaked a bunch of scripts to achieve op
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.
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.
