Application debugging skills in PHP mall development

PHP mall development is one of the most popular mall applications in today's Internet era. Especially in the field of e-commerce, PHP mall development is widely used. However, in the process of implementing PHP mall development, you will inevitably encounter some problems that are difficult to debug. This article will focus on application debugging techniques in PHP mall development.

1. Basic debugging skills

1. Output debugging information

During the PHP development process, we can determine whether the code is correct by adding a method to output debugging information in the code. The operation is normal and the variables are assigned correctly. Common methods are:

• echo($var): Output the value of the variable $var to the browser and display it at the corresponding location in the HTML code.
• print_r($arr): Output the detailed structure information of array $arr to the browser.
• var_dump($var): Output the detailed information of the variable, including variable type, length, value, etc.

2. Write log file

In addition, you can write debugging information to the log file for better troubleshooting. Writing debugging information to log files can also avoid throwing too much information to users in the production environment and affecting the user experience.

There is a function error_log() in the PHP standard library, which can write debugging information to the system error log. The parameter list includes the information to be written to the log, the location to write the log to, and the error level. For example:

• error_log("Debug information", 3, "/var/log/php_errors.log");

Here, parameter 1 means to write Log information; parameter 2 represents the log writing method, 3 represents the log content to be appended to the end of the file; parameter 3 is the location of the log file to be written.

3. Use breakpoint debugging

Breakpoint debugging is a method of stopping code execution when it reaches a specific location for debugging. In PHP mall development, using breakpoint debugging can greatly improve debugging efficiency.

There are usually two ways to debug breakpoints in PHP. The first is to use a PHP integrated development environment, such as PhpStorm, etc., by clicking the left mouse button in front of the code line number to establish a breakpoint and execute the program. The program will pause execution at the breakpoint location. The second is to use the xdebug extension to use the location where the code pauses execution as a breakpoint, and hand over the debugging information to debugging tools (such as PhpStorm) for processing.

2. Advanced debugging skills

1. Debugging performance bottleneck

When we are processing a large amount of data, the performance of the program is very important, so the debugging performance bottleneck is also Very critical.

PHP integrates the xdebug extension and provides a module called xdebug_profiler. This module collects and analyzes application performance data and outputs the results to a file.

The code to open the xdebug_profiler module is as follows:

• xdebug_start_profiling();

The code to exit the xdebug_profiler module and save the analysis results is as follows:

• xdebug_stop_profiling();
• $data = xdebug_get_profiler_filename();

2. Debugging of the running environment

When our PHP mall application After being deployed to a production environment, the running of the code is often affected by more factors, such as hardware environment, system configuration, network bandwidth, etc. If there is a problem with any of these factors, it can cause the application to malfunction or even become inaccessible.

In this case, we need to debug the running environment. This process is complex and requires the use of various tools. Here is a brief introduction to commonly used tools.

• strace: This tool can be used to trace an application's system calls to help find time-consuming operations.
• netstat: This tool can be used to check TCP/UDP connection status and help find network-related problems.
• top: This tool can display the list of processes currently running on the system and the usage of system resources.

3. Summary

In PHP mall development, the importance of debugging skills is self-evident. The basic debugging skills and advanced debugging skills introduced in this article can help us locate problems faster, reduce development time, and improve work efficiency. However, even if we have sufficient debugging skills, we cannot ignore improving the quality and readability of the code. This is what makes an excellent PHP mall development expert.

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