Let's talk about how to display error prompts in php

PHP is a popular server-side scripting language that can be used to develop various web applications. During the development process of PHP, errors are inevitable. PHP provides some methods available to display errors, which helps programmers identify errors quickly. In this article, we will explore how to display PHP error messages.

1. Types of PHP error prompts

In PHP, there are three types of error prompts:

1. Notices (Notes) : This is the least serious type of error and is usually triggered by minor errors such as using undefined variables.
2. Warnings (warnings): Generally more serious problems, such as trying to use undefined functions or variables.
3. Errors: This is the most serious type of error and usually means that the code cannot continue to execute, such as syntax errors or inability to connect to the database.

2. Error prompts in the PHP configuration file

In the PHP configuration file php.ini, there are some instructions that can control the system error prompts.

1. display_errors: This is a Boolean directive used to control whether to display PHP errors.
2. error_reporting: This is an integer type directive used to control which error types PHP reports.

By default, both display_errors and error_reporting directives are set to on.

If you do not want PHP to output error information directly to the user, you can turn off the error prompt by setting display_errors to Off in php.ini. This is because turning on error prompts can leak important information when the application is deployed to a production environment.

3. Set error prompts in PHP scripts

If you only want to display error information in a certain PHP script, you can use error_reporting() and ini_set() function.

1. error_reporting() function: This function is used to set which error types PHP reports. Here are some examples:

(1) Show only critical errors: error_reporting(E_ERROR | E_PARSE);

(2) Show all error types: error_reporting(E_ALL);

(3) Close the error prompt: error_reporting(0);

2. ini_set() function: This function is used to dynamically change the instructions in php.ini. The following are some examples:

(1) Turn on error prompts: ini_set('display_errors', 1);

(2) Turn off error prompts: ini_set('display_errors', 0 );

(3) Set the error level: ini_set('error_reporting', E_ALL);

4. PHP error log

In PHP , all error messages can be logged to the server's error log file. You can use this log to diagnose and resolve errors.

In the php.ini file, the log_errors directive controls the opening and closing of the error logging mechanism. If set to On, PHP will log all errors to the error log file. By default, this command is enabled.

Some web servers (such as Apache) provide a tool to access the error log, and you can view all errors on the server from this tool.

5. Error prompts of the PHP framework

When using the PHP framework, the framework usually provides more convenient error prompts. For example, the Laravel framework provides an error() function. When an error occurs, this function will automatically output the error message to the page.

6. Conclusion

In the development process of PHP applications, error prompts are very important. Developers need to quickly identify errors and take action. In PHP, you can better control and manage error information by turning off error prompts, setting error levels, and viewing error logs. At the same time, when using the PHP framework, the error prompts provided by the framework can also help developers handle errors more easily.

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