In C++, an exception is a way of handling errors or unexpected situations that occur during the execution of a program. It allows the program to gracefully handle these errors without crashing or producing unpredictable results.

An exception is thrown when an error or exceptional situation is encountered during the execution of a program. This can include things like division by zero, attempting to access an invalid memory address, or trying to open a file that doesn’t exist. When an exception is thrown, the program stops executing and looks for an exception handler to deal with the situation.

Exception handling in C++ involves two main concepts: throwing an exception and catching an exception. When an exception is thrown, the program looks for a catch block that can handle the exception. If no catch block is found, the program terminates with an error message.

To throw an exception in C++, you use the throw keyword followed by an exception object. For example:

int divide(int a, int b) {
    if (b == 0) {
        throw "Division by zero error";
    }
    return a / b;
}

In this example, the function divide() checks if the second argument is zero and throws a string exception if it is. This will stop the execution of the function and look for a catch block that can handle the exception.

To catch an exception in C++, you use a try-catch block. A try block contains the code that may throw an exception, and a catch block contains the code that will handle the exception. For example:

try {
    int result = divide(10, 0);
    cout << "The result is " << result << endl;
}
catch (const char* error) {
    cerr << "An error occurred: " << error << endl;
}

In this example, the code inside the try block calls the divide() function with arguments 10 and 0, which will throw an exception. The catch block catches the exception and prints an error message to the console.

When catching an exception, you can specify the type of exception that you want to catch. This allows you to handle different types of exceptions in different ways. For example:

try {
    // code that may throw exceptions
}
catch (const char* error) {
    // handle string exceptions
}
catch (int error) {
    // handle integer exceptions
}
catch (...) {
    // handle all other exceptions
}

In this example, the catch block with a string argument will handle string exceptions, the catch block with an integer argument will handle integer exceptions, and the catch block with ellipsis (…) will handle all other types of exceptions.

In summary, exception handling in C++ allows you to gracefully handle errors and unexpected situations in your program. To use exception handling, you need to throw an exception when an error occurs and catch the exception in a try-catch block. You can specify different catch blocks to handle different types of exceptions, and you can use the ellipsis to catch all other types of exceptions.

Follow us on Twitter: Hacktube5