这个问题出在那里？
<body><br /><form action="index.php" method="post"><br />输入A：<input type="text" name="c"/><br><br />输入B：<input type="text" name="d"/><br /><input type="submit" value="Submit"/><br /></form><br /><?php<br /> function jisuan(&$a,&$b){<br /> $c=$a+$b;<br /> echo 'a+b='.$c."<br/>";<br /> }<br /> if(isset($_POST['c']) && isset($_POST['d']))<br /> {<br /> $x=$_POST['c'];<br /> $y=$_POST['d'];<br /> jisuan($x,$y);<br /> }<br /> else <br /> echo "结果为0！";<br />?><br /></body>一直提示没有定义 c 和 d。是什么原因？
------解决方案--------------------
程序正常啊 没有你说的错误
------解决方案--------------------
没有发现有什么错误。请完整贴出代码和出错信息。
------解决方案--------------------
程序是正常的。
------解决方案--------------------
<?php<br /> function jisuan(&$a,&$b){<br /> $c=$a+$b;<br /> echo 'a+b='.$c."<br/>";<br /> }<br /> if(isset($_POST['c']) && isset($_POST['d']))<br /> {<br /> $x=$_POST['c'];<br /> $y=$_POST['d'];<br /> jisuan($x,$y);<br /> }<br /> else <br /> echo "结果为0！";<br />?>新建一个index.php 文件 把上面的文件 剪切里面 ，运行 HTML 页面
------解决方案--------------------
error_reporting(0);
How does PHP identify a user's session?May 01, 2025 am 12:23 AMPHPidentifiesauser'ssessionusingsessioncookiesandsessionIDs.1)Whensession_start()iscalled,PHPgeneratesauniquesessionIDstoredinacookienamedPHPSESSIDontheuser'sbrowser.2)ThisIDallowsPHPtoretrievesessiondatafromtheserver.
What are some best practices for securing PHP sessions?May 01, 2025 am 12:22 AMThe security of PHP sessions can be achieved through the following measures: 1. Use session_regenerate_id() to regenerate the session ID when the user logs in or is an important operation. 2. Encrypt the transmission session ID through the HTTPS protocol. 3. Use session_save_path() to specify the secure directory to store session data and set permissions correctly.
Where are PHP session files stored by default?May 01, 2025 am 12:15 AMPHPsessionfilesarestoredinthedirectoryspecifiedbysession.save_path,typically/tmponUnix-likesystemsorC:\Windows\TemponWindows.Tocustomizethis:1)Usesession_save_path()tosetacustomdirectory,ensuringit'swritable;2)Verifythecustomdirectoryexistsandiswrita
How do you retrieve data from a PHP session?May 01, 2025 am 12:11 AMToretrievedatafromaPHPsession,startthesessionwithsession_start()andaccessvariablesinthe$_SESSIONarray.Forexample:1)Startthesession:session_start().2)Retrievedata:$username=$_SESSION['username'];echo"Welcome,".$username;.Sessionsareserver-si
How can you use sessions to implement a shopping cart?May 01, 2025 am 12:10 AMThe steps to build an efficient shopping cart system using sessions include: 1) Understand the definition and function of the session. The session is a server-side storage mechanism used to maintain user status across requests; 2) Implement basic session management, such as adding products to the shopping cart; 3) Expand to advanced usage, supporting product quantity management and deletion; 4) Optimize performance and security, by persisting session data and using secure session identifiers.
How do you create and use an interface in PHP?Apr 30, 2025 pm 03:40 PMThe article explains how to create, implement, and use interfaces in PHP, focusing on their benefits for code organization and maintainability.
What is the difference between crypt() and password_hash()?Apr 30, 2025 pm 03:39 PMThe article discusses the differences between crypt() and password_hash() in PHP for password hashing, focusing on their implementation, security, and suitability for modern web applications.
How can you prevent Cross-Site Scripting (XSS) in PHP?Apr 30, 2025 pm 03:38 PMArticle discusses preventing Cross-Site Scripting (XSS) in PHP through input validation, output encoding, and using tools like OWASP ESAPI and HTML Purifier.
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
Zend Studio 13.0.1
Powerful PHP integrated development environment
MantisBT
Mantis is an easy-to-deploy web-based defect tracking tool designed to aid in product defect tracking. It requires PHP, MySQL and a web server. Check out our demo and hosting services.
mPDF
mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),
WebStorm Mac version
Useful JavaScript development tools
VSCode Windows 64-bit Download
A free and powerful IDE editor launched by Microsoft
