Question

Write a program segment that defines a file stream object named employees. The file should be opened for both input and output (in binary mode). If the file fails to open, the program segment should display an error message.

Short answer

After analyzing the problem and looking at the solution provided, the short answer is: To define a file stream object named "employees" and open it in binary mode for both input and output, follow the steps below: 1. Include the necessary libraries `iostream` and `fstream` to work with file streams 2. Define a file stream object named "employees" using the `std::fstream` class 3. Open the file using the `open()` method with the required filename and appropriate file opening modes: `std::ios::in`, `std::ios::out`, and `std::ios::binary` 4. Check if the file has been opened successfully using the `is_open()` method; if the file fails to open, display an error message and exit the program.

Step-by-step solution

1. Include necessary libraries

To work with file streams, include the following libraries in the program: ```cpp #include #include ```

2. Define the file stream object

Define the file stream object named "employees" using the fstream class. The fstream class is the combination of ifstream and ofstream classes, allowing the file to be opened for both input and output. ```cpp std::fstream employees; ```

3. Open the file in binary mode

Open the file using the open() method with the required filename and appropriate file opening modes. In this case, we want to open it for both input and output, and in binary mode. We will use ios::in, ios::out, and ios::binary flags. ```cpp employees.open("employees.dat", std::ios::in | std::ios::out | std::ios::binary); ```

4. Check if the file is opened successfully

Check if the file has been opened successfully by using the is_open() method. If the file fails to open, display an error message and exit the program. ```cpp if (!employees.is_open()) { std::cerr << "Error: Failed to open the file." << std::endl; return 1; } ```

Full code

Here's the complete program segment according to the given exercise: ```cpp #include #include int main() { // Step 1 // Step 2 std::fstream employees; // Step 3 employees.open("employees.dat", std::ios::in | std::ios::out | std::ios::binary); // Step 4 if (!employees.is_open()) { std::cerr << "Error: Failed to open the file." << std::endl; return 1; } // ... Perform file operations ... // Close the file employees.close(); return 0; } ```