3.Write a program that has a class student that stores roll number, name, and marks (in three subjects) of the students. Display the information (roll number, name, and total marks) stored about the student?

#include <stdio.h>

// Define the student class
struct Student {
    int rollNumber;
    char name[50];
    int marks[3];
};

int main() {
    // Create an instance of the student class
    struct Student student;

    // Get input from the user
    printf("Enter roll number: ");
    scanf("%d", &student.rollNumber);
    printf("Enter name: ");
    scanf("%s", student.name);
    printf("Enter marks in three subjects: ");
    for (int i = 0; i < 3; i++) {
        scanf("%d", &student.marks[i]);
    }

    // Calculate the total marks
    int totalMarks = 0;
    for (int i = 0; i < 3; i++) {
        totalMarks += student.marks[i];
    }

    // Display the information stored about the student
    printf("Roll number: %d\n", student.rollNumber);
    printf("Name: %s\n", student.name);
    printf("Total marks: %d\n", totalMarks);

    return 0;
}

Explanation:

1. We start by including the necessary header file stdio.h which contains the functions for input/output operations.
2. Next, we define a struct Student to represent the student class. It has three members: rollNumber to store the roll number, name to store the name (as a character array), and marks to store the marks in three subjects (as an integer array).
3. In the main() function, we create an instance of the Student struct called student.
4. We use printf() and scanf() functions to get input from the user. First, we prompt the user to enter the roll number, name, and marks in three subjects, and then we use scanf() to read the input and store it in the corresponding members of the student struct.
5. We use a loop to calculate the total marks by iterating over the marks array and adding up the values.
6. Finally, we use printf() to display the information stored about the student, including the roll number, name, and total marks.
7. The program ends by returning 0 from the main() function.