How to read php error messages

PHP is a very powerful programming language, but when writing code, errors often occur. When an error occurs, PHP returns an error message, which can help us find the problem in the code and fix it. This article will explain how to view PHP error messages to quickly find and solve the problem.

1. View PHP configuration file

In the PHP configuration file, you can find relevant error message settings. By modifying these settings, you can control how and at what level error messages are displayed. The configuration file in PHP is usually the php.ini file. In the code, the configuration information can also be modified through the ini_set() function.

For example, when an error occurs, you can turn on the display of all error messages by setting error_reporting(E_ALL). In addition, setting display_errors = On enables real-time display of error messages, which is helpful for debugging code.

2. Check the log file

PHP also provides a log function, which can write error information to the specified log file. These log files are usually located in the server's log directory. By examining these log files, you can learn more detailed error information so you can better debug your code.

In the php.ini file, we can set error_log to define the path of the log file. Typically, the location of the log file may be /var/log/php_errors or /var/log/apache2/error_log.

3. Use the browser to display error messages

PHP also provides a simple way to display error messages on a web page. This method does not print out all error messages, but only includes information that may be useful during debugging.

In the php.ini file, we can set html_errors = On to display error messages in the browser. When this option is turned on, PHP will output the error message in HTML format and display it in the browser. This feature is only used during testing to avoid error messages in production environments.

4. Print error message

Printing error message is one of the most common methods when debugging PHP code. By adding variable variables, debugging information, or log statements to your PHP code, you can discover where and why errors occur.

For example, by adding echo 'hello' to the code, you can determine whether the code segment is executed correctly. In addition, use the var_dump() function to print out detailed information about objects, arrays, and variables to better analyze errors.

Summary

When writing PHP code, we often encounter various errors. Knowing how to view PHP error messages can help us find and solve problems faster. By modifying PHP configuration files, viewing PHP log files, using the browser to print error information, and printing debugging information in the code, we can locate and fix errors more effectively. In the event of a problem, remember to check out the PHP documentation and community for additional help and support.

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