search
HomeBackend DevelopmentPHP Tutorial回调函数 - php 手册里关于callback 类型中有一句话我不是很理解

回调函数 - php 手册里关于callback 类型中有一句话我不是很理解
未捕获的异常,官网没有给 demo,我也没想到有什么异常, 看到的大神能不能帮忙写个简单的例子 谢谢了

回复内容:

回调函数 - php 手册里关于callback 类型中有一句话我不是很理解
未捕获的异常,官网没有给 demo,我也没想到有什么异常, 看到的大神能不能帮忙写个简单的例子 谢谢了

很好理解啊。

比如一个函数中你注册了两个回调,示例代码:

function somefunc1(){
    //some code...
    //Throw a exception
    throw new \Exception('I am a exception!');
}

function somefunc2(){
    //some code...
    //Not throw a exception
}

恰好,在你执行的时候, somefunc1() 的异常被抛出来了,这时候,在你的要使用的回调函数的函数中,你必须:

try {
    call_user_func('somefunc1');
} catch (\Exception $e) {
    echo $e->getMessage();
}
//以下函数在异常时候会继续执行
call_user_func('somefunc2');

如果你没有像上述那样子去捕获异常,代码示例如下:

call_user_func('somefunc1');
//当异常抛出的时候,一下代码不会继续执行
call_user_func('somefunc2');

以上。

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
How does PHP identify a user's session?How does PHP identify a user's session?May 01, 2025 am 12:23 AM

PHPidentifiesauser'ssessionusingsessioncookiesandsessionIDs.1)Whensession_start()iscalled,PHPgeneratesauniquesessionIDstoredinacookienamedPHPSESSIDontheuser'sbrowser.2)ThisIDallowsPHPtoretrievesessiondatafromtheserver.

What are some best practices for securing PHP sessions?What are some best practices for securing PHP sessions?May 01, 2025 am 12:22 AM

The 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?Where are PHP session files stored by default?May 01, 2025 am 12:15 AM

PHPsessionfilesarestoredinthedirectoryspecifiedbysession.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?How do you retrieve data from a PHP session?May 01, 2025 am 12:11 AM

ToretrievedatafromaPHPsession,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?How can you use sessions to implement a shopping cart?May 01, 2025 am 12:10 AM

The 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?How do you create and use an interface in PHP?Apr 30, 2025 pm 03:40 PM

The 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()?What is the difference between crypt() and password_hash()?Apr 30, 2025 pm 03:39 PM

The 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?How can you prevent Cross-Site Scripting (XSS) in PHP?Apr 30, 2025 pm 03:38 PM

Article discusses preventing Cross-Site Scripting (XSS) in PHP through input validation, output encoding, and using tools like OWASP ESAPI and HTML Purifier.

See all articles

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

WebStorm Mac version

WebStorm Mac version

Useful JavaScript development tools

Dreamweaver Mac version

Dreamweaver Mac version

Visual web development tools

ZendStudio 13.5.1 Mac

ZendStudio 13.5.1 Mac

Powerful PHP integrated development environment

PhpStorm Mac version

PhpStorm Mac version

The latest (2018.2.1) professional PHP integrated development tool

EditPlus Chinese cracked version

EditPlus Chinese cracked version

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