Exploration on the principle of C++ function exceptions: Understand the bottom layer of exception handling

C Exception handling principle: Throwing an exception: Use the throw keyword to throw an exception object. Catching exceptions: Use the catch keyword to catch specific types of exceptions. try-catch block: Place the code segment in a try-catch block to handle exceptions. Practical case: The throwError() function throws an exception, and the main() function uses the try-catch block to print the error message. Custom exceptions: Custom exception classes derived from std::exception can be created to represent application-specific errors.

Exploration on the principle of C function exceptions: Understand the underlying exception handling

Introduction

Exception handling is a C language feature for handling errors or unexpected conditions. When an exception occurs, the program throws an object, which is called an exception. The exception handling mechanism allows developers to catch and handle these exceptions in an elegant way, thereby improving the robustness and maintainability of the code.

Exception handling principle

C’s exception handling mechanism consists of three main parts:

• throw: Used to throw an exception.
• catch: Used to handle a specific exception type.
• try-catch block: Enclose a piece of code within which to handle exceptions.

Practical Case

The following is a simple practical case to demonstrate how to use exception handling:

#include <iostream>

using namespace std;

void throwError() {
  throw runtime_error("An error occurred");
}

int main() {
  try {
    throwError();
  }
  catch (runtime_error& e) {
    cout << "Error: " << e.what() << endl;
  }

  return 0;
}

In this case, throwError() The function throws a runtime_error exception with an error message. The main() function uses a try-catch block to catch the exception and print the error message.

Custom Exceptions

C allows developers to create custom exception classes to represent specific errors in their applications. Custom exception classes must derive from the std::exception base class.

Here's how to create a custom exception class:

class MyException : public std::exception {
public:
  const char* what() const noexcept override {
    return "My custom exception";
  }
};

Using custom exceptions in code looks like this:

try {
  // 代码可能会引发 MyException 异常
}
catch (MyException& e) {
  // 处理 MyException 异常
}

Conclusion

Exception handling is an important language feature in C for handling errors and unexpected conditions. Understanding the principles of exception handling is critical to writing robust and maintainable code.

The above is the detailed content of Exploration on the principle of C++ function exceptions: Understand the bottom layer of exception handling. For more information, please follow other related articles on the PHP Chinese website!