How to handle exceptions and errors using PHP

Exception and error handling in PHP: Exception: a non-fatal error that the program can recover from, handled using the try-catch structure. Error: A serious error that the program cannot recover from, use the error_handler function to handle it. Practical case: catch FileNotFoundException exception and display friendly message, handle TypeError error and display error message.

How to handle exceptions and errors with PHP

Exceptions and errors are an inevitable part of PHP. Handling them properly is crucial to writing robust and reliable applications.

Exceptions and Errors

• Exceptions are non-fatal errors that occur during program execution and from which the program can recover.
• Errors are serious errors from which the program cannot recover.

Handling exceptions

PHP uses the try-catch structure to handle exceptions:

try {
    // 代码块可能抛出异常
} catch (Exception $e) {
    // 异常处理代码
}

Practical combat Case

Consider the following code, which attempts to read a file that does not exist:

try {
    $file = fopen('non-existent.txt', 'r');
} catch (Exception $e) {
    echo "文件不存在";
}

When the script runs, it catches the FileNotFoundException exception and displays a friendly information.

Handling errors

PHP sets the error_handler function to handle errors:

set_error_handler(function($errno, $errstr, $errfile, $errline) {
    // 错误处理代码
});

Practical case

Consider the following code, which attempts to convert a string to an integer:

$number = (int) "abc";

This triggers a TypeError error. We can set the following error handler to handle it:

set_error_handler(function($errno, $errstr, $errfile, $errline) {
    echo "错误: {$errstr} ({$errfile}:{$errline})";
});

After the script runs, it will display the error message: "Error: Invalid argument supplied for foreach() (err.php:12)".

The above is the detailed content of How to handle exceptions and errors using PHP. For more information, please follow other related articles on the PHP Chinese website!