Untitled
unknown
plain_text
10 months ago
3.6 kB
2
Indexable
Never
Certainly, let's go through the code step by step and explain its functionality: 1. Include necessary header files: ```cpp #include <iostream> #include <fstream> #include <string> ``` These lines include the required C++ standard library headers for input/output, file handling, and working with strings. 2. Define a `Student` struct: ```cpp struct Student { int id; std::string name; }; ``` This struct defines the structure of a student, containing two fields: `id` (an integer representing the student's ID) and `name` (a string representing the student's name). 3. Function `writeStudentData`: ```cpp void writeStudentData(const std::string& filename, const Student& student) { // Open the file in append mode std::ofstream outFile(filename, std::ios::app); if (outFile.is_open()) { outFile << student.id << " " << student.name << "\n"; outFile.close(); std::cout << "Student information has been written to the file." << std::endl; } else { std::cerr << "Error: Unable to open the file for writing." << std::endl; } } ``` - This function takes two parameters: a filename and a `Student` object. - It opens the file specified by the filename in append mode (`std::ios::app`) and writes the student's ID and name to the file, separated by a space. - It then closes the file and prints a message to indicate whether the operation was successful. 4. Function `readStudentData`: ```cpp void readStudentData(const std::string& filename) { // Open the file for reading std::ifstream inFile(filename); if (inFile.is_open()) { Student student; while (inFile >> student.id) { inFile.get(); // Consume the space character std::getline(inFile, student.name); std::cout << "Student ID: " << student.id << ", Student Name: " << student.name << std::endl; } inFile.close(); } else { std::cerr << "Error: Unable to open the file for reading." << std::endl; } } ``` - This function takes a filename as a parameter and opens the file for reading using `std::ifstream`. - It reads student information from the file line by line. It extracts the ID as an integer and consumes the space character before reading the student's name as a string. - The student information is then displayed, and the file is closed. 5. The `main` function: - It defines a constant string `filename` as the name of the file where student data is stored. - Inside a while loop, it presents a menu to the user, allowing them to: - Add a student (enter ID and name). - Display all students' information. - Quit the program. - For adding a student, the program reads the student's ID and name, and for displaying all students, it reads and prints all student information from the file. - The program keeps running until the user chooses to quit by entering '3'. - It uses `std::cin` and `std::cout` for input and output and correctly handles student names with spaces using `getline` and consuming the newline characters. - Error messages are displayed if there are issues with file operations. In summary, this C++ program provides a simple file-based system for storing and retrieving student information, including student IDs and names, using functions and a menu-driven interface.