C Mini Project – Student Management System

Our mini project will manage basic student information.

The program will store:

• Student ID
• Student name
• Marks
• Grade

The application will use a menu so that the user can select different operations.

Our Student Management System will contain the following features:

• Add student
• Display all students
• Search student by ID
• Update student marks
• Calculate grade
• Save records to a file
• Exit the program

A structure is suitable for storing different types of information about one student.

struct Student
{
    int id;
    char name[50];
    float marks;
    char grade;
};

Each student can now contain an ID, name, marks, and grade.

We can use an array of structures to store multiple students.

#define MAX_STUDENTS 100

struct Student students[MAX_STUDENTS];

int studentCount = 0;

The studentCount variable keeps track of how many students are currently stored.

Our project uses several standard C library features.

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

stdio.h is used for input/output and files, stdlib.h provides general-purpose functions, and string.h provides string functions.

We can create a separate function to determine a student's grade.

char calculateGrade(float marks)
{
    if(marks >= 90)
        return 'A';
    else if(marks >= 75)
        return 'B';
    else if(marks >= 60)
        return 'C';
    else if(marks >= 40)
        return 'D';
    else
        return 'F';
}

Marks should normally be between 0 and 100. We can validate the value before storing it.

if(marks < 0 || marks > 100)
{
    printf("Invalid marks!\n");
}

Input validation helps prevent invalid data from entering the system.

The addStudent() function can collect information from the user and store it in the array.

void addStudent(struct Student students[],
                int *count)
{
    if(*count >= MAX_STUDENTS)
    {
        printf("Student limit reached.\n");
        return;
    }

    printf("Enter student ID: ");
    scanf("%d", &students[*count].id);

    printf("Enter student name: ");
    scanf(" %49[^\n]", students[*count].name);

    printf("Enter marks: ");
    scanf("%f", &students[*count].marks);

    students[*count].grade =
        calculateGrade(students[*count].marks);

    (*count)++;

    printf("Student added successfully.\n");
}

The addStudent() function needs to update the original student count. A pointer allows the function to modify the variable in the calling function.

void addStudent(struct Student students[],
                int *count)

The expression (*count)++ increases the original count.

A separate function can display the details of one student.

void displayStudent(struct Student s)
{
    printf("ID    : %d\n", s.id);
    printf("Name  : %s\n", s.name);
    printf("Marks : %.2f\n", s.marks);
    printf("Grade : %c\n", s.grade);
}

We can use a loop to display every student in the array.

void displayAll(struct Student students[],
                int count)
{
    int i;

    if(count == 0)
    {
        printf("No students available.\n");
        return;
    }

    for(i = 0; i < count; i++)
    {
        printf("\nStudent %d\n", i + 1);
        displayStudent(students[i]);
    }
}

We can search the array using the student's ID.

int findStudent(struct Student students[],
                int count,
                int id)
{
    int i;

    for(i = 0; i < count; i++)
    {
        if(students[i].id == id)
        {
            return i;
        }
    }

    return -1;
}

Returning -1 means that the student was not found.

The search function can use findStudent() and display the matching record.

void searchStudent(struct Student students[],
                   int count)
{
    int id;
    int index;

    printf("Enter student ID: ");
    scanf("%d", &id);

    index = findStudent(students, count, id);

    if(index == -1)
    {
        printf("Student not found.\n");
    }
    else
    {
        displayStudent(students[index]);
    }
}

We can allow the user to update the marks of an existing student.

void updateMarks(struct Student students[],
                 int count)
{
    int id;
    int index;
    float marks;

    printf("Enter student ID: ");
    scanf("%d", &id);

    index = findStudent(students, count, id);

    if(index == -1)
    {
        printf("Student not found.\n");
        return;
    }

    printf("Enter new marks: ");
    scanf("%f", &marks);

    if(marks < 0 || marks > 100)
    {
        printf("Invalid marks.\n");
        return;
    }

    students[index].marks = marks;
    students[index].grade = calculateGrade(marks);

    printf("Marks updated successfully.\n");
}

The project can save student information to a text file using fopen().

FILE *file;

file = fopen("students.txt", "w");

if(file == NULL)
{
    printf("Unable to open file.\n");
    return;
}

Always check whether the file was opened successfully.

void saveStudents(struct Student students[],
                  int count)
{
    FILE *file;
    int i;

    file = fopen("students.txt", "w");

    if(file == NULL)
    {
        printf("Unable to open file.\n");
        return;
    }

    for(i = 0; i < count; i++)
    {
        fprintf(file, "%d|%s|%.2f|%c\n",
                students[i].id,
                students[i].name,
                students[i].marks,
                students[i].grade);
    }

    fclose(file);

    printf("Students saved successfully.\n");
}

We can also load previously saved records when the program starts.

void loadStudents(struct Student students[],
                  int *count)
{
    FILE *file;

    file = fopen("students.txt", "r");

    if(file == NULL)
    {
        return;
    }

    while(*count < MAX_STUDENTS &&
          fscanf(file, "%d|%49[^|]|%f|%c\n",
                 &students[*count].id,
                 students[*count].name,
                 &students[*count].marks,
                 &students[*count].grade) == 4)
    {
        (*count)++;
    }

    fclose(file);
}

A menu makes the application easier to use.

printf("\n===== Student Management =====\n");
printf("1. Add Student\n");
printf("2. Display Students\n");
printf("3. Search Student\n");
printf("4. Update Marks\n");
printf("5. Save Students\n");
printf("6. Exit\n");
printf("Enter choice: ");

The switch statement is suitable for processing menu choices.

switch(choice)
{
    case 1:
        addStudent(students, &studentCount);
        break;

    case 2:
        displayAll(students, studentCount);
        break;

    case 3:
        searchStudent(students, studentCount);
        break;

    default:
        printf("Invalid choice.\n");
}

A do-while loop can keep displaying the menu until the user chooses to exit.

do
{
    printf("\n1. Add Student");
    printf("\n2. Display Students");
    printf("\n3. Search Student");
    printf("\n4. Update Marks");
    printf("\n5. Save Students");
    printf("\n6. Exit");

    printf("\nEnter choice: ");
    scanf("%d", &choice);

} while(choice != 6);

switch(choice)
{
    case 1:
        addStudent(students, &studentCount);
        break;

    case 2:
        displayAll(students, studentCount);
        break;

    case 3:
        searchStudent(students, studentCount);
        break;

    case 4:
        updateMarks(students, studentCount);
        break;

    case 5:
        saveStudents(students, studentCount);
        break;

    case 6:
        saveStudents(students, studentCount);
        printf("Goodbye!\n");
        break;

    default:
        printf("Invalid choice.\n");
}

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define MAX_STUDENTS 100

struct Student
{
    int id;
    char name[50];
    float marks;
    char grade;
};

char calculateGrade(float marks)
{
    if(marks >= 90)
        return 'A';
    else if(marks >= 75)
        return 'B';
    else if(marks >= 60)
        return 'C';
    else if(marks >= 40)
        return 'D';
    else
        return 'F';
}

int findStudent(struct Student students[],
                int count,
                int id)
{
    int i;

    for(i = 0; i < count; i++)
    {
        if(students[i].id == id)
            return i;
    }

    return -1;
}

void addStudent(struct Student students[],
                int *count)
{
    float marks;

    if(*count >= MAX_STUDENTS)
    {
        printf("Student limit reached.\n");
        return;
    }

    printf("Enter ID: ");
    scanf("%d", &students[*count].id);

    printf("Enter name: ");
    scanf(" %49[^\n]", students[*count].name);

    printf("Enter marks: ");
    scanf("%f", &marks);

    if(marks < 0 || marks > 100)
    {
        printf("Invalid marks.\n");
        return;
    }

    students[*count].marks = marks;
    students[*count].grade = calculateGrade(marks);

    (*count)++;

    printf("Student added successfully.\n");
}

void displayStudent(struct Student s)
{
    printf("\nID    : %d\n", s.id);
    printf("Name  : %s\n", s.name);
    printf("Marks : %.2f\n", s.marks);
    printf("Grade : %c\n", s.grade);
}

void displayAll(struct Student students[],
                int count)
{
    int i;

    if(count == 0)
    {
        printf("No students available.\n");
        return;
    }

    for(i = 0; i < count; i++)
    {
        printf("\nStudent %d", i + 1);
        displayStudent(students[i]);
    }
}

void searchStudent(struct Student students[],
                   int count)
{
    int id;
    int index;

    printf("Enter ID: ");
    scanf("%d", &id);

    index = findStudent(students, count, id);

    if(index == -1)
    {
        printf("Student not found.\n");
    }
    else
    {
        displayStudent(students[index]);
    }
}

void updateMarks(struct Student students[],
                 int count)
{
    int id;
    int index;
    float marks;

    printf("Enter ID: ");
    scanf("%d", &id);

    index = findStudent(students, count, id);

    if(index == -1)
    {
        printf("Student not found.\n");
        return;
    }

    printf("Enter new marks: ");
    scanf("%f", &marks);

    if(marks < 0 || marks > 100)
    {
        printf("Invalid marks.\n");
        return;
    }

    students[index].marks = marks;
    students[index].grade = calculateGrade(marks);

    printf("Marks updated successfully.\n");
}

void saveStudents(struct Student students[],
                  int count)
{
    FILE *file;
    int i;

    file = fopen("students.txt", "w");

    if(file == NULL)
    {
        printf("Unable to open file.\n");
        return;
    }

    for(i = 0; i < count; i++)
    {
        fprintf(file, "%d|%s|%.2f|%c\n",
                students[i].id,
                students[i].name,
                students[i].marks,
                students[i].grade);
    }

    fclose(file);

    printf("Data saved successfully.\n");
}

int main()
{
    struct Student students[MAX_STUDENTS];

    int studentCount = 0;
    int choice;

    do
    {
        printf("\n\n===== STUDENT MANAGEMENT =====\n");
        printf("1. Add Student\n");
        printf("2. Display Students\n");
        printf("3. Search Student\n");
        printf("4. Update Marks\n");
        printf("5. Save Students\n");
        printf("6. Exit\n");

        printf("Enter choice: ");
        scanf("%d", &choice);

        switch(choice)
        {
            case 1:
                addStudent(students, &studentCount);
                break;

            case 2:
                displayAll(students, studentCount);
                break;

            case 3:
                searchStudent(students, studentCount);
                break;

            case 4:
                updateMarks(students, studentCount);
                break;

            case 5:
                saveStudents(students, studentCount);
                break;

            case 6:
                saveStudents(students, studentCount);
                printf("Goodbye!\n");
                break;

            default:
                printf("Invalid choice.\n");
        }

    } while(choice != 6);

    return 0;
}

1. The program starts from main().
2. The student array is created.
3. The menu is displayed.
4. The user selects an operation.
5. The corresponding function is called.
6. Student information is stored in the structure array.
7. Grades are calculated from marks.
8. Students can be searched or updated.
9. Records can be saved to a file.
10. The menu continues until the user selects Exit.

After completing the basic project, you can add more features.

• Delete student
• Load students automatically at startup
• Search by student name
• Sort students by marks
• Calculate class average
• Display highest and lowest marks
• Add attendance
• Add course information
• Use multiple source files
• Create a separate header file

These improvements can turn the mini project into a larger C application.

Now create your own improved Student Management System.

Your final version should include:

1. Add student
2. Display all students
3. Search student
4. Update student
5. Delete student
6. Calculate grade
7. Find highest marks
8. Find lowest marks
9. Calculate average marks
10. Save and load records from a file

Try to divide the project into multiple files such as main.c, student.c, and student.h. This will give you practical experience with modular C programming.