How to handle errors in C++ functions?

Best practices for handling errors in C include using exceptions to handle exceptional situations and using error codes to indicate non-fatal errors. Exceptions throw custom error messages, which are caught and handled through try-catch blocks; error codes are used for minor errors and are handled through if-else statements after checking. By throwing an exception and using a try-catch block, serious errors can be caught gracefully, while smaller errors can be represented with error codes and handled on a case-by-case basis.

Best Practices for Handling Errors in C Functions

In C programs, it is crucial to handle errors effectively to ensure Application robustness and providing meaningful feedback to users. The following are best practices for handling errors:

1. Use exceptions

Exceptions are a standardized mechanism for handling abnormal situations. They provide an elegant and structured way to catch and handle errors without explicitly checking the error code.

// 定义一个抛出 std::runtime_error 异常的函数
void my_function() {
  throw std::runtime_error("错误发生！");
}

// 使用 try-catch 块捕获异常
try {
  my_function();
} catch (const std::runtime_error& e) {
  std::cout << "错误： " << e.what() << std::endl;
}

2. Error Codes

Error codes can be used for errors that are less serious or do not require interruption of program flow. Error codes are integers or enumeration values ​​that represent specific error conditions.

enum class ErrorCode {
  NoError,
  InvalidInput,
  FileOpenError,
};

// 定义一个返回错误代码的函数
ErrorCode my_function() {
  // 检查错误条件
  if (invalid_input) {
    return ErrorCode::InvalidInput;
  }
  // ...

  return ErrorCode::NoError;
}

// 检查并处理错误代码
auto error_code = my_function();
if (error_code == ErrorCode::InvalidInput) {
  std::cout << "无效输入" << std::endl;
} else if (error_code == ErrorCode::FileOpenError) {
  std::cout << "文件打开错误" << std::endl;
}

Practical case:

Suppose we are writing a function that reads a file. If the file does not exist or cannot be opened, we want to throw an exception and handle this exception in the main function.

// 定义文件读取函数
std::string read_file(const std::string& filename) {
  std::ifstream file(filename);
  if (!file.is_open()) {
    throw std::runtime_error("无法打开文件：" + filename);
  }

  // ... 读取文件内容

  return file.str();
}

// 在主函数中使用 try-catch 块处理异常
int main() {
  try {
    auto file_content = read_file("my_file.txt");
    // 使用文件内容
  } catch (const std::runtime_error& e) {
    std::cout << "错误： " << e.what() << std::endl;
  }

  return 0;
}

The above is the detailed content of How to handle errors in C++ functions?. For more information, please follow other related articles on the PHP Chinese website!