How to debug and handle errors in PHP development

PHP is a popular server-side language used for developing web applications. As a programmer, debugging and error handling are unavoidable. In this article, I will take you through how to debug and handle errors in PHP development.

1. Turn on error reporting

In PHP, error reporting is turned off by default. If we want to see errors in PHP code, we need to open error reporting manually. We can use the error reporting function error_reporting() to turn on or off PHP error reporting.

For example, we can set the error report to show all levels of errors:

error_reporting(E_ALL);

2. Print debugging information

In PHP code, we can Use the print_r() and var_dump() functions to print the values ​​and attributes of variables to better understand the execution of the code.

For example, we can print out an array:

$arr = array('apple', 'banana', 'orange');
print_r($arr);

Output:

Array
(
    [0] => apple
    [1] => banana
    [2] => orange
)

3. Using Xdebug

Xdebug is a PHP Extension that can be used to debug PHP code. It provides some great debugging tools and features, such as breakpoint debugging, single-stepping, variable monitoring, stack tracing, etc.

To use Xdebug, you need to first install the Xdebug extension and configure it in the php.ini file. Then, use your favorite IDE to debug. Many common PHP IDEs, such as PhpStorm, NetBeans and VSCode, support XDebug debugging.

For example, in PhpStorm you can enable Xdebug, set breakpoints and start debugging, then pause execution at lines in the code to view the stack, variable and expression values.

4. Using try-catch block

In PHP, we can use try-catch block to handle exceptions and errors. You can write code that may cause exceptions in a try block and catch and handle these exceptions in a catch block. This feature is useful because if something goes wrong in your code, it helps you figure out the problem without directly causing your code to crash.

For example:

try {
    // 可能会抛出异常的代码
} catch(Exception $e) {
    // 异常抛出后，请在这里处理它
    echo 'Caught exception: ',  $e->getMessage(), "
";
}

5. Turn off error prompts

Finally, when you deploy a PHP application, it is very important to turn off PHP error prompts to prevent leaks Sensitive information to potential attackers. You can turn off PHP error prompts in a production environment to avoid unnecessary security risks.

Find the following setting in the php.ini file and set it to off:

display_errors = off
log_errors = on

In short, debugging and error handling are very important during the PHP development process. Whether you are developing locally or deploying your application, debugging is an essential tool. With the right tools and skills, you can quickly locate and resolve errors, making your code more efficient, stable, and reliable.

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