How does PHP handle errors gracefully?

Error handling in PHP provides an elegant way to handle errors: catch exceptions using try-catch statements. Use the set_error_handler function to customize error handling. Use the debug_backtrace function to debug errors. Practical case: database error: use try-catch statement to capture database query failure. File upload errors: Use the set_error_handler function to log errors and display a friendly message to the user.

Elegant Error Handling in PHP

Introduction

Error handling is any A vital part of web applications. By handling errors gracefully, you can provide a friendly experience for end users and prevent unexpected outages.

Using the try-catch statement

try-catch statement is a powerful tool for dealing with possible Exception code block:

try {
    // 您的代码
} catch (Exception $e) {
    // 错误处理代码
}

Using the set_error_handler function The

##set_error_handler function allows you to customize the error handler. This is useful for creating custom error messages and logging errors:

set_error_handler(function ($error_level, $error_message, $error_file, $error_line) {
    // 自定义错误处理代码
});

Using the debug_backtrace function

debug_backtrace function returns Array of current execution stack. This is very useful for debugging errors and finding the source of the error:

if (isset($error)) {
    $trace = debug_backtrace();
    // 打印执行堆栈
    print_r($trace);
}

practical case

Case 1: Database error

When the database query fails, use the

try-catch statement to handle the error gracefully:

try {
    $result = $db->query($query);
} catch (PDOException $e) {
    echo "抱歉，数据库出现问题：" . $e->getMessage();
}

Case 2: File upload error

When When the file upload fails, use the

set_error_handler function to log the error and display a friendly message to the user:

set_error_handler(function ($error_level, $error_message) {
    if ($error_level & E_WARNING) {
        error_log($error_message);
        echo "抱歉，文件上传失败，请重试";
    }
});

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