The art of PHP debugging, a guide from scratch to mastery

You can effectively debug PHP code by enabling error reporting, using var_dump() and print_r() to display variables, setting breakpoints (such as using Xdebug), recording debugging information, installing PHP debugging tools, and using a log management system. .

The Art of PHP Debugging

Debugging is a critical part of the software development process, it helps to find and fix errors in your code The problem. For PHP developers, mastering debugging skills is crucial and can significantly speed up the development process.

Zero Basic Debugging Guide

1. Enable error reporting

By default, PHP will suppress certain errors and warn. To get as much information as possible, enable error reporting:

ini_set('display_errors', 1);
error_reporting(E_ALL);

2. Use var_dump() and print_r()

These functions can be used to display the contents of variables . They are very useful in debugging to quickly see the value and type of a variable:

var_dump($variable);
print_r($array);

3. Set breakpoints

Xdebug is a PHP extension that allows you to set Breakpoints and pause execution at specific lines of code. This allows you to step through code and examine the values ​​of variables.

How to install and use Xdebug is beyond the scope of this article, but you can check out the official documentation for more information.

Practical case

Consider the following code snippet:

function sum($a, $b) {
  return $a + $b;
}

$result = sum(5, 10);

Suppose the function returns the wrong result. The following debugging steps will help you find the problem:

1. Enable error reporting and run the code.
2. Check the error message. You may get errors about undefined variables ($a, $b).
3. Use var_dump() to check the content of the parameters passed to the function:

var_dump($a);
var_dump($b);

4. The result will be an empty array ([]), which indicates that the function's parameters are empty. Examining the code, I found that the function was defined to accept a reference parameter, but the parameter passed to it was not a reference.

Advanced Debugging Tips

• Use log files to record debugging information.
• Install PHP debugging tools such as Scout or PhpStorm.
• Use a custom log management system, such as Monolog.

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