PHP Error & Exception Handling

PHP Error Handling:

In PHP, errors can occur when the code encounters something that prevents it from executing normally. These errors are called runtime errors or exceptions. PHP provides a built-in error handling mechanism that allows you to catch and handle these errors gracefully.

There are three types of errors in PHP:

1. Notices: These are non-critical errors that occur when PHP encounters a problem, but it can still continue executing the code.
2. Warnings: These are more serious errors that indicate a problem with the code. The code can still execute, but it may not function correctly.
3. Fatal errors: These are critical errors that prevent the code from executing further. The script will stop running when it encounters a fatal error.

To handle errors in PHP, you can use the following functions:

1. error_reporting(): This function sets the level of error reporting. You can set it to display all errors, no errors, or a specific level of errors.
2. ini_set(): This function allows you to set specific settings in the php.ini file. You can use it to turn error reporting on or off.
3. trigger_error(): This function allows you to trigger your own error messages. You can use it to handle errors in a custom way.

PHP Exception Handling:

In addition to error handling, PHP also supports exception handling. Exceptions are a way of handling errors that occur during runtime in a more controlled way. Instead of stopping the script like a fatal error would, exceptions can be caught and handled in a way that allows the script to continue running.

To use exception handling in PHP, you need to use the try-catch block. The try block contains the code that you want to run, and the catch block contains the code that will handle the exception if one is thrown.

Here’s an example of how to use exception handling in PHP:

try {
    // Code that may throw an exception
} catch (Exception $e) {
    // Code that handles the exception
}

In this example, if an exception is thrown in the try block, the catch block will handle it. The $e variable contains information about the exception that was thrown, such as the error message and the line number where it occurred.

You can also create your own custom exceptions in PHP by extending the built-in Exception class. This allows you to define your own error messages and handling for specific types of errors that may occur in your code.