#include <iostream>
using namespace std;
// Base class Student
class Student {
protected:
int rollno;
string name;
public:
void get_student_details() {
cout << “Enter roll number: “;
cin >> rollno;
cout << “Enter name: “;
cin >> name; }
void put_student_details() {
cout << “Roll number: ” << rollno << endl;
cout << “Name: ” << name << endl; } };
// Derived class Exam
class Exam : public Student {
private:
int marks[5];
public:
void get_marks() {
cout << “Enter marks in 5 subjects:\n”;
for (int i = 0; i < 5; i++) {
cin >> marks[i]; } } };
// Derived class Result
class Result : public Exam {
private:
int total;
float avg;
public:
void calculate_result() {
total = 0;
for (int i = 0; i < 5; i++) {
total += marks[i]; }
avg = total / 5.0; }
void display_result() {
put_student_details(); // Call base class function
cout << “Total marks: ” << total << endl;
cout << “Average: ” << avg << endl; } };
int main() {
Result student1;
cout << “\nEnter student details and marks:\n”;
student1.get_student_details();
student1.get_marks();
student1.calculate_result();
cout << “\nStudent result:\n”;
student1.display_result();
return 0;
}
Output:
Enter student details and marks:
Enter roll number: 123
Enter name: Priya
Enter marks in 5 subjects:
80 75 90 85 95
Student result:
Roll number: 123
Name: Priya
Total marks: 425
Average: 85.00
Here’s a step-by-step explanation of the code:
1. Header and Namespace:
- #include <iostream>: Includes the iostream header for input/output operations.
- using namespace std;: Brings the std namespace into scope for convenient use of its elements.
2. Base Class Student:
- class Student { … }: Defines the base class Student, representing basic student information.
- protected: int rollno; string name;: Protected members, accessible to derived classes, for roll number and name.
- public: void get_student_details() { … }; void put_student_details() { … };: Public member functions to get and display student details.
3. Derived Class Exam:
- class Exam : public Student { … }: Derived class representing exam details, inheriting from Student.
- private: int marks[5];: Private member to store marks in 5 subjects.
- public: void get_marks() { … };: Public member function to get marks from the user.
4. Derived Class Result:
- class Result : public Exam { … }: Derived class representing exam results, inheriting from Exam.
- private: int total; float avg;: Private members to store total marks and average.
- public: void calculate_result() { … }; void display_result() { … };: Public member functions to calculate and display results.
5. Main Function:
- int main() { … }: The program’s entry point.
- Result student1;: Creates an object of the Result class.
- **Prompts for student details and marks, calling appropriate functions.
- **Calculates and displays the result using Result class me
