Project: Student Report Card

Let's build a real program that uses almost everything from this course. It reads a class of students and their marks, then prints a neat report.

The plan

• A struct holds one student: name, three marks, and the average.
• A function works out the average.
• A function turns an average into a grade letter.
• main reads the data, then prints a table and the top student.

The program

#include <stdio.h>

typedef struct {
    char name[20];
    int marks[3];
    double average;
} Student;

double averageOf(int *marks, int count) {
    int total = 0;
    for (int i = 0; i < count; i++) {
        total += marks[i];
    }
    return (double) total / count;
}

char gradeFor(double avg) {
    if (avg >= 90) {
        return 'A';
    } else if (avg >= 75) {
        return 'B';
    } else if (avg >= 50) {
        return 'C';
    }
    return 'F';
}

int main() {
    int n;
    Student cls[30];
    scanf("%d", &n);
    for (int i = 0; i < n; i++) {
        scanf("%s %d %d %d", cls[i].name, &cls[i].marks[0], &cls[i].marks[1], &cls[i].marks[2]);
        cls[i].average = averageOf(cls[i].marks, 3);
    }

    printf("%-10s %7s  %s\n", "Name", "Average", "Grade");
    int top = 0;
    for (int i = 0; i < n; i++) {
        printf("%-10s %7.1f  %c\n", cls[i].name, cls[i].average, gradeFor(cls[i].average));
        if (cls[i].average > cls[top].average) {
            top = i;
        }
    }
    printf("Top student: %s\n", cls[top].name);
    return 0;
}

Input (what the user types)

4
Asha 92 88 95
Ben 70 65 80
Cara 45 50 40
Dev 85 90 78

Output

Name       Average  Grade
Asha          91.7  A
Ben           71.7  C
Cara          45.0  F
Dev           84.3  B
Top student: Asha

What to notice

• Each function does one small job and has a clear name.
• cls[i].marks is an array inside a struct inside an array – and it all still works with [ ] and ..
• %-10s and %7.1f line the table up.

Tip: Try changing it: add a fourth mark, or print how many students got each grade.