**Course Title:** Modern C++ Programming: Mastering C++ with Best Practices and Advanced Techniques **Section Title:** Error Handling and Exceptions **Topic:** Develop a C++ program that gracefully handles errors and exceptions.(Lab topic) ## Introduction In this topic, we will explore how to develop a C++ program that effectively handles errors and exceptions. We will delve into the concept of exception handling, discuss the best practices for writing exception-safe code, and demonstrate how to implement exception handling mechanisms in a C++ program. ## Understanding Exceptions In C++, an exception is an abnormal event that occurs during the execution of a program. Exceptions can be caused by errors such as division by zero, out-of-range values, or resource allocation failures. When an exception occurs, the program's normal flow of execution is disrupted, and the program may terminate abruptly if not handled properly. ### Types of Exceptions There are two types of exceptions in C++: * **Synchronous exceptions**: These exceptions occur during the execution of a program and are typically caused by errors such as division by zero or out-of-range values. * **Asynchronous exceptions**: These exceptions occur due to external events, such as hardware failures or system crashes. ## Exception Handling in C++ C++ provides a built-in mechanism for handling exceptions using try-catch blocks. The syntax for a try-catch block is as follows: ```cpp try { // Code that may throw an exception } catch (ExceptionType e) { // Code that handles the exception } ``` ### Exception Types C++ provides several built-in exception types, including: * `std::exception`: The base class for all exceptions. * `std::runtime_error`: A subclass of `std::exception` that represents runtime errors. * `std::logic_error`: A subclass of `std::exception` that represents logic errors. You can also define your own custom exception types by deriving from the `std::exception` class. ### Example: Handling Exceptions ```cpp #include <iostream> #include <stdexcept> void divide(int a, int b) { if (b == 0) { throw std::runtime_error("Division by zero!"); } int result = a / b; std::cout << "Result: " << result << std::endl; } int main() { try { divide(10, 0); } catch (const std::exception& e) { std::cerr << "Error: " << e.what() << std::endl; return 1; } return 0; } ``` In this example, we define a `divide` function that throws a `std::runtime_error` exception if the denominator is zero. We then catch this exception in the `main` function and print an error message. ### Best Practices for Writing Exception-Safe Code 1. **Use try-catch blocks**: Use try-catch blocks to handle exceptions and prevent program termination. 2. **Keep exception handling local**: Handle exceptions as close to the source of the exception as possible. 3. **Avoid using `std::terminate`**: Avoid using `std::terminate` to handle exceptions, as it can lead to program termination. 4. **Use `std::exception` as the base class**: Derive your custom exception types from `std::exception`. ### Exercise Develop a C++ program that handles errors and exceptions when reading a file. Use try-catch blocks to handle exceptions and prevent program termination. ### Additional Resources * [C++ Exception Handling Tutorial](https://www.cplusplus.com/doc/tutorial/exceptions/) * [C++ Exception Handling Best Practices](https://en.cppreference.com/w/cpp/language/exceptions) ### Comments and Feedback If you have any questions or need help with this topic, please leave a comment below. We will respond to your comment as soon as possible. --- This concludes our topic on developing a C++ program that gracefully handles errors and exceptions. In the next topic, we will explore unit testing in C++ using testing frameworks like Google Test and Catch2.