php之session熟悉了解
概念了解:
session在web主要指用户在浏览某个网站,从进入该网站到关闭这个网站经过的这段时间。
工作原理:
1.启动seesion,服务端会传给浏览器一个键值为PHPSESSID的唯一标识存储在本地的cookie中,同时会在服务器相应目录下根据键值生成一个对应的session文件
设置session值后,值就存在该session文件中
2.服务器php脚本读取session值的话,浏览器传回键值的唯一标识,通过启动session,然后根据键值可以从session文件中加载已经存储的变量
3.当php脚本执行结束时,未被销毁的session变量会被自动保存在本地一定路径下唯一标识的session文件中,路径可以通过php.ini中的session.save_path设定
1.设置session值,得先启动session,后设置
session_start();$_SESSION['name'] = 'wyz';
2.读取session值
session_start();echo $_SESSION['name'];
a.针对单个
unset($_SESSION['name']);
b.针对所有
session_destroy();
4.设置session的唯一标识值cookie在浏览器上的保留时间,也可以说设置存放session值的时间
session_start(); $_SESSION['name'] = 'wyzss';$lifeTime = 24 * 3600;setcookie(session_name(), session_id(), time() + $lifeTime, "/");
注:设置php.ini下的gc_maxlifetime只能保证session生存的最短时间

What’s still popular is the ease of use, flexibility and a strong ecosystem. 1) Ease of use and simple syntax make it the first choice for beginners. 2) Closely integrated with web development, excellent interaction with HTTP requests and database. 3) The huge ecosystem provides a wealth of tools and libraries. 4) Active community and open source nature adapts them to new needs and technology trends.

PHP and Python are both high-level programming languages that are widely used in web development, data processing and automation tasks. 1.PHP is often used to build dynamic websites and content management systems, while Python is often used to build web frameworks and data science. 2.PHP uses echo to output content, Python uses print. 3. Both support object-oriented programming, but the syntax and keywords are different. 4. PHP supports weak type conversion, while Python is more stringent. 5. PHP performance optimization includes using OPcache and asynchronous programming, while Python uses cProfile and asynchronous programming.

PHP is mainly procedural programming, but also supports object-oriented programming (OOP); Python supports a variety of paradigms, including OOP, functional and procedural programming. PHP is suitable for web development, and Python is suitable for a variety of applications such as data analysis and machine learning.

PHP originated in 1994 and was developed by RasmusLerdorf. It was originally used to track website visitors and gradually evolved into a server-side scripting language and was widely used in web development. Python was developed by Guidovan Rossum in the late 1980s and was first released in 1991. It emphasizes code readability and simplicity, and is suitable for scientific computing, data analysis and other fields.

PHP is suitable for web development and rapid prototyping, and Python is suitable for data science and machine learning. 1.PHP is used for dynamic web development, with simple syntax and suitable for rapid development. 2. Python has concise syntax, is suitable for multiple fields, and has a strong library ecosystem.

PHP remains important in the modernization process because it supports a large number of websites and applications and adapts to development needs through frameworks. 1.PHP7 improves performance and introduces new features. 2. Modern frameworks such as Laravel, Symfony and CodeIgniter simplify development and improve code quality. 3. Performance optimization and best practices further improve application efficiency.

PHPhassignificantlyimpactedwebdevelopmentandextendsbeyondit.1)ItpowersmajorplatformslikeWordPressandexcelsindatabaseinteractions.2)PHP'sadaptabilityallowsittoscaleforlargeapplicationsusingframeworkslikeLaravel.3)Beyondweb,PHPisusedincommand-linescrip

PHP type prompts to improve code quality and readability. 1) Scalar type tips: Since PHP7.0, basic data types are allowed to be specified in function parameters, such as int, float, etc. 2) Return type prompt: Ensure the consistency of the function return value type. 3) Union type prompt: Since PHP8.0, multiple types are allowed to be specified in function parameters or return values. 4) Nullable type prompt: Allows to include null values and handle functions that may return null values.


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