Do you know how to customize error handling functions and error masking in PHP?-PHP Tutorial-php.cn

Home

Backend Development

PHP Tutorial

Do you know how to customize error handling functions and error masking in PHP?

WBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWB

Oct 21, 2021 pm 05:57 PM

php Error handling

In the previous article, I brought you "Take you to understand the error types and error levels of PHP", which introduced the error types and error levels in PHP in detail. In this article we Let’s take a look at how to customize error handling and how to block errors in PHP. I hope it will be helpful to everyone!

Do you know how to customize error handling functions and error masking in PHP?

In our daily development, it is inevitable to encounter errors. Sometimes we can specify a function as an error handling function. There is a custom error in PHP processing function.

set_error_handler() ##Function custom error handling function

PHP provides the set_error_handler() function, which is used to specify a function as an error handling function. Its syntax format is as follows:

set_error_handler(自定义函数名 [, int $error_types = E_ALL | E_STRICT ])

Copy after login

The syntax format of this custom function name is as follows:

error_handler(int 错误的级别 , string 错误的信息 [, string 发生错误的文件名 [, int 发生错误的行号 ]])

Copy after login

If there is an error handler defined before, the returned program name is the program name of the modified program; if it is a built-in error handler, the returned result is NULL. If an invalid callback function is specified, NULL will also be returned.

Next let’s take a look at an example, customize an error handling function, and use it to handle errors in the program. The example is as follows:

<?php
    function error_handler($errno, $errstr, $errfile, $errline ) {
        echo "error number：".$errno."<br/>";
        echo "error msg：".$errstr."<br/>";
        echo "error file：".$errfile."<br/>";
        echo "error line：".$errline."<br/>";
        die(&#39;something error&#39;);
    }
    set_error_handler("error_handler");
    strpos();
?>

Copy after login

Output results :

Do you know how to customize error handling functions and error masking in PHP?

#What we need to pay attention to when using this function is that we only use this method for error handling. If the function has no errors, or the program does not When running in the wrong function, the program will continue to execute the function statement where the error occurred, so we need to use the die() function to terminate the function.

In our daily development, exceptions in the program cannot be thrown automatically. At this time, we can also use set_error_handler() to customize and handle the exception as an error, so that we can use Customize error handling to automatically catch exceptions.

The example is as follows:

<?php
    function error_handler($errno, $errstr, $errfile, $errline ) {
        echo "error number：".$errno."<br/>";
        echo "error msg：".$errstr."<br/>";
        echo "error file：".$errfile."<br/>";
        echo "error line：".$errline."<br/>";
        die(&#39;something error&#39;);
    }
    set_error_handler("error_handler");
    /* 触发异常 */
    try {
        $a = 5/0;//程序会自动捕捉这个异常，并且由自定义函数来处理
        echo $a;
    } catch(Exception $e) {
        echo $e->getMessage();
    }
?>

Copy after login

Output result:

Do you know how to customize error handling functions and error masking in PHP?

##Error maskingIn the PHP development process, we can not only handle errors by customizing the error handling function through set_error_handler(), but we can also mask errors. In some cases, error masking is also essential. Next, I will list some methods for error shielding.

@##---Error control operator
In PHP, if the error control operator @ is placed in front of an expression, any errors that may exist in the expression will be blocked.

Regarding the use of @, we need to note that the @ operator will only take effect when placed in front of an expression. For example, the @ operator can be used in front of variables, functions, constants, etc. , must not be placed before the definition of a function or class, nor can it be placed in front of a conditional structure statement.

The example is as follows:

<?php
    $link = @mysqli_connect("127.0.0.1", "my_user", "my_password", "my_db") or die(&#39;数据库连接失败！&#39;);
?>

Copy after login

Output result:

In the above example, it can be seen that @ Error control operator, which can mask expressions before expressions. Do you know how to customize error handling functions and error masking in PHP?

Use
error_reporting() Function to shield errors##PHP There are many error levels in PHP. You can use the error_reporting() function to set what kind of errors PHP will report. The syntax format of the function is as follows:
```
error_reporting(设置错误级别)
```
Copy after login

PHP's error types and error levels are introduced in more detail. Next, let's look at the use of functions through examples:

<?php
    error_reporting(0);
    $link = mysqli_connect("127.0.0.1", "my_user", "my_password", "my_db") or die(&#39;数据库连接失败！&#39;);
?>

Copy after login

Output results:

Do you know how to customize error handling functions and error masking in PHP?
##Mask errors through the

display_errors

This method is the most thorough method. The first two methods only work on a single line or a single file, but masking errors through the display_errors parameter works on all PHP files. Let’s take a look at what to do. Do it. First we need to open the
php.ini

(In the previous article "How to upload files in PHP? You will understand after reading it!" introduced the relevant knowledge on how to remove php and ini configuration files)

Examples are as follows:

Do you know how to customize error handling functions and error masking in PHP?

This way you can block errors.

If you are interested, you can click on "PHP Video Tutorial" to learn more about PHP knowledge.

The above is the detailed content of Do you know how to customize error handling functions and error masking in PHP?. For more information, please follow other related articles on the PHP Chinese website!

Statement of this Website

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

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

What's New in Windows 11 KB5054979 & How to Fix Update Issues

1 months ago By DDD

How to fix KB5055523 fails to install in Windows 11?

3 weeks ago By DDD

How to fix KB5055518 fails to install in Windows 10?

3 weeks ago By DDD

Strength Levels for Every Enemy & Monster in R.E.P.O.

3 weeks ago By 尊渡假赌尊渡假赌尊渡假赌

Blue Prince: How To Get To The Basement

3 weeks ago By DDD

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

Java Tutorial

1653

CakePHP Tutorial

1413

Laravel Tutorial

1305

PHP Tutorial

1251

C# Tutorial

1224

Related knowledge

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,

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

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.

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

PHP and Python: Comparing Two Popular Programming Languages Apr 14, 2025 am 12:13 AM

PHP and Python each have their own advantages, and choose according to project requirements. 1.PHP is suitable for web development, especially for rapid development and maintenance of websites. 2. Python is suitable for data science, machine learning and artificial intelligence, with concise syntax and suitable for beginners.

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.

PHP: A Key Language for Web Development Apr 13, 2025 am 12:08 AM

PHP is a scripting language widely used on the server side, especially suitable for web development. 1.PHP can embed HTML, process HTTP requests and responses, and supports a variety of databases. 2.PHP is used to generate dynamic web content, process form data, access databases, etc., with strong community support and open source resources. 3. PHP is an interpreted language, and the execution process includes lexical analysis, grammatical analysis, compilation and execution. 4.PHP can be combined with MySQL for advanced applications such as user registration systems. 5. When debugging PHP, you can use functions such as error_reporting() and var_dump(). 6. Optimize PHP code to use caching mechanisms, optimize database queries and use built-in functions. 7

PHP in Action: Real-World Examples and Applications Apr 14, 2025 am 12:19 AM

PHP is widely used in e-commerce, content management systems and API development. 1) E-commerce: used for shopping cart function and payment processing. 2) Content management system: used for dynamic content generation and user management. 3) API development: used for RESTful API development and API security. Through performance optimization and best practices, the efficiency and maintainability of PHP applications are improved.

See all articles