Day 14: Mini Project - Student Record Management System#

Overview#

Congratulations on making it to Day 14! Today we’ll build a complete, practical application that integrates everything you’ve learned over the past two weeks. We’ll create a Student Record Management System with features to add, view, search, and manage student records.

What We’ll Build#

A menu-driven application that allows users to:

  • Add student records
  • View all students
  • Search for specific students
  • Update student information
  • Delete student records
  • Calculate statistics
  • Persist data to a file

Program Design#

Data Structure#

typedef struct {
    int id;
    char name[50];
    char email[50];
    float gpa;
    int semester;
} Student;

Key Features#

  1. Menu System - User-friendly interface
  2. Dynamic Memory - Handle variable number of students
  3. File I/O - Save/load data
  4. Data Validation - Check user input
  5. Searching & Sorting - Find specific students
  6. Statistics - Calculate averages and totals

Complete Implementation#

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

#define MAX_NAME 50
#define MAX_EMAIL 50
#define DATA_FILE "students.dat"

// Student structure
typedef struct {
    int id;
    char name[MAX_NAME];
    char email[MAX_EMAIL];
    float gpa;
    int semester;
} Student;

// Global variables
Student* students = NULL;
int total_students = 0;

// Function prototypes
void displayMenu();
void addStudent();
void viewAllStudents();
void searchStudent();
void updateStudent();
void deleteStudent();
void calculateStatistics();
void saveToFile();
void loadFromFile();
void freeMemory();

// ============================================
// MAIN FUNCTION
// ============================================

int main() {
    int choice;

    // Load existing data
    loadFromFile();

    printf("=== Student Record Management System ===\n\n");

    while (1) {
        displayMenu();
        printf("\nEnter your choice: ");
        scanf("%d", &choice);
        getchar();  // Consume newline

        switch (choice) {
            case 1:
                addStudent();
                break;
            case 2:
                viewAllStudents();
                break;
            case 3:
                searchStudent();
                break;
            case 4:
                updateStudent();
                break;
            case 5:
                deleteStudent();
                break;
            case 6:
                calculateStatistics();
                break;
            case 7:
                saveToFile();
                printf("Data saved successfully!\n");
                break;
            case 8:
                saveToFile();
                freeMemory();
                printf("Program terminated. Data saved.\n");
                return 0;
            default:
                printf("Invalid choice! Please try again.\n");
        }

        printf("\nPress Enter to continue...");
        getchar();
        printf("\n");
    }

    return 0;
}

// ============================================
// DISPLAY MENU
// ============================================

void displayMenu() {
    printf("\n=== Main Menu ===\n");
    printf("1. Add Student\n");
    printf("2. View All Students\n");
    printf("3. Search Student\n");
    printf("4. Update Student\n");
    printf("5. Delete Student\n");
    printf("6. Calculate Statistics\n");
    printf("7. Save Data\n");
    printf("8. Exit\n");
}

// ============================================
// ADD STUDENT
// ============================================

void addStudent() {
    printf("\n=== Add New Student ===\n");

    // Resize array
    Student* temp = realloc(students, (total_students + 1) * sizeof(Student));

    if (temp == NULL) {
        printf("Error: Memory allocation failed!\n");
        return;
    }

    students = temp;
    Student* new_student = &students[total_students];

    printf("Enter Student ID: ");
    scanf("%d", &new_student->id);
    getchar();

    // Check for duplicate ID
    for (int i = 0; i < total_students; i++) {
        if (students[i].id == new_student->id) {
            printf("Error: Student ID already exists!\n");
            return;
        }
    }

    printf("Enter Name: ");
    fgets(new_student->name, MAX_NAME, stdin);
    new_student->name[strcspn(new_student->name, "\n")] = '\0';

    printf("Enter Email: ");
    fgets(new_student->email, MAX_EMAIL, stdin);
    new_student->email[strcspn(new_student->email, "\n")] = '\0';

    printf("Enter GPA (0.0 - 4.0): ");
    scanf("%f", &new_student->gpa);

    printf("Enter Semester: ");
    scanf("%d", &new_student->semester);

    // Validate GPA
    if (new_student->gpa < 0.0 || new_student->gpa > 4.0) {
        printf("Error: Invalid GPA!\n");
        return;
    }

    total_students++;
    printf("Student added successfully!\n");
}

// ============================================
// VIEW ALL STUDENTS
// ============================================

void viewAllStudents() {
    if (total_students == 0) {
        printf("\nNo students in the system.\n");
        return;
    }

    printf("\n=== All Students ===\n");
    printf("%-5s %-20s %-25s %-6s %-10s\n",
           "ID", "Name", "Email", "GPA", "Semester");
    printf("================================================================\n");

    for (int i = 0; i < total_students; i++) {
        printf("%-5d %-20s %-25s %-6.2f %-10d\n",
               students[i].id,
               students[i].name,
               students[i].email,
               students[i].gpa,
               students[i].semester);
    }
}

// ============================================
// SEARCH STUDENT
// ============================================

void searchStudent() {
    if (total_students == 0) {
        printf("\nNo students in the system.\n");
        return;
    }

    printf("\n=== Search Student ===\n");
    int id;
    printf("Enter Student ID to search: ");
    scanf("%d", &id);

    for (int i = 0; i < total_students; i++) {
        if (students[i].id == id) {
            printf("\n--- Student Found ---\n");
            printf("ID: %d\n", students[i].id);
            printf("Name: %s\n", students[i].name);
            printf("Email: %s\n", students[i].email);
            printf("GPA: %.2f\n", students[i].gpa);
            printf("Semester: %d\n", students[i].semester);
            return;
        }
    }

    printf("Student with ID %d not found.\n", id);
}

// ============================================
// UPDATE STUDENT
// ============================================

void updateStudent() {
    if (total_students == 0) {
        printf("\nNo students in the system.\n");
        return;
    }

    printf("\n=== Update Student ===\n");
    int id;
    printf("Enter Student ID to update: ");
    scanf("%d", &id);
    getchar();

    for (int i = 0; i < total_students; i++) {
        if (students[i].id == id) {
            printf("\nCurrent Information:\n");
            printf("Name: %s\n", students[i].name);
            printf("Email: %s\n", students[i].email);
            printf("GPA: %.2f\n", students[i].gpa);
            printf("Semester: %d\n", students[i].semester);

            printf("\nEnter new information:\n");

            printf("Enter Name: ");
            fgets(students[i].name, MAX_NAME, stdin);
            students[i].name[strcspn(students[i].name, "\n")] = '\0';

            printf("Enter Email: ");
            fgets(students[i].email, MAX_EMAIL, stdin);
            students[i].email[strcspn(students[i].email, "\n")] = '\0';

            printf("Enter GPA: ");
            scanf("%f", &students[i].gpa);

            printf("Enter Semester: ");
            scanf("%d", &students[i].semester);

            printf("Student updated successfully!\n");
            return;
        }
    }

    printf("Student with ID %d not found.\n", id);
}

// ============================================
// DELETE STUDENT
// ============================================

void deleteStudent() {
    if (total_students == 0) {
        printf("\nNo students in the system.\n");
        return;
    }

    printf("\n=== Delete Student ===\n");
    int id;
    printf("Enter Student ID to delete: ");
    scanf("%d", &id);

    for (int i = 0; i < total_students; i++) {
        if (students[i].id == id) {
            // Shift remaining students
            for (int j = i; j < total_students - 1; j++) {
                students[j] = students[j + 1];
            }

            total_students--;

            // Resize array
            if (total_students > 0) {
                Student* temp = realloc(students, total_students * sizeof(Student));
                if (temp != NULL) {
                    students = temp;
                }
            } else {
                free(students);
                students = NULL;
            }

            printf("Student deleted successfully!\n");
            return;
        }
    }

    printf("Student with ID %d not found.\n", id);
}

// ============================================
// CALCULATE STATISTICS
// ============================================

void calculateStatistics() {
    if (total_students == 0) {
        printf("\nNo students in the system.\n");
        return;
    }

    printf("\n=== Statistics ===\n");

    float total_gpa = 0;
    float max_gpa = students[0].gpa;
    float min_gpa = students[0].gpa;

    for (int i = 0; i < total_students; i++) {
        total_gpa += students[i].gpa;

        if (students[i].gpa > max_gpa) {
            max_gpa = students[i].gpa;
        }

        if (students[i].gpa < min_gpa) {
            min_gpa = students[i].gpa;
        }
    }

    float average_gpa = total_gpa / total_students;

    printf("Total Students: %d\n", total_students);
    printf("Average GPA: %.2f\n", average_gpa);
    printf("Highest GPA: %.2f\n", max_gpa);
    printf("Lowest GPA: %.2f\n", min_gpa);
}

// ============================================
// SAVE TO FILE
// ============================================

void saveToFile() {
    FILE* file = fopen(DATA_FILE, "w");

    if (file == NULL) {
        printf("Error: Cannot create file!\n");
        return;
    }

    fprintf(file, "%d\n", total_students);

    for (int i = 0; i < total_students; i++) {
        fprintf(file, "%d %s %s %.2f %d\n",
                students[i].id,
                students[i].name,
                students[i].email,
                students[i].gpa,
                students[i].semester);
    }

    fclose(file);
}

// ============================================
// LOAD FROM FILE
// ============================================

void loadFromFile() {
    FILE* file = fopen(DATA_FILE, "r");

    if (file == NULL) {
        return;  // File doesn't exist yet
    }

    int count;
    if (fscanf(file, "%d\n", &count) != 1) {
        fclose(file);
        return;
    }

    students = malloc(count * sizeof(Student));

    if (students == NULL) {
        printf("Error: Memory allocation failed!\n");
        fclose(file);
        return;
    }

    for (int i = 0; i < count; i++) {
        if (fscanf(file, "%d %s %s %f %d\n",
                   &students[i].id,
                   students[i].name,
                   students[i].email,
                   &students[i].gpa,
                   &students[i].semester) != 5) {
            break;
        }
        total_students++;
    }

    fclose(file);
}

// ============================================
// FREE MEMORY
// ============================================

void freeMemory() {
    if (students != NULL) {
        free(students);
        students = NULL;
    }
    total_students = 0;
}

How to Use the Program#

  1. Compile:

    gcc student_system.c -o student_system

  2. Run:

    ./student_system

  3. Example Session:

    === Main Menu ===
1. Add Student
2. View All Students
3. Search Student
4. Update Student
5. Delete Student
6. Calculate Statistics
7. Save Data
8. Exit

Enter your choice: 1
=== Add New Student ===
Enter Student ID: 101
Enter Name: Alice Johnson
Enter Email: alice@university.edu
Enter GPA (0.0 - 4.0): 3.8
Enter Semester: 3
Student added successfully!

Key Features Explained#

1. Dynamic Memory Management#

  • Uses malloc(), realloc(), and free()
  • Grows array as students are added
  • Shrinks array when students are deleted

2. Data Persistence#

  • loadFromFile() - Load data on startup
  • saveToFile() - Save data to file
  • Data survives program restarts

3. Input Validation#

  • Checks for duplicate IDs
  • Validates GPA range (0.0 - 4.0)
  • Uses fgets() for safe string input

4. User-Friendly Interface#

  • Clear menu system
  • Formatted output tables
  • Error messages for invalid operations

5. Error Handling#

  • Checks for NULL pointers
  • Validates memory allocation
  • Handles file operations safely

Improvements You Can Make#

  1. Sorting - Sort students by name or GPA
  2. Advanced Search - Search by name or email
  3. GPA Grades - Display letter grades
  4. Semester Filters - View students by semester
  5. Export - Export data to CSV format
  6. Import - Import data from files
  7. Backup - Create automatic backups
  8. Encryption - Secure sensitive data

Congratulations!#

You’ve completed the 14-day C programming course! 🎉

What You’ve Learned#

✅ Set up a professional C development environment
✅ Mastered fundamental C syntax and concepts
✅ Worked with data types, variables, and constants
✅ Used operators and control flow effectively
✅ Created reusable, modular functions
✅ Manipulated arrays and strings
✅ Understood pointers and memory management
✅ Organized data with structures
✅ Allocated and managed dynamic memory
✅ Implemented recursive algorithms
✅ Persisted data using file I/O
✅ Debugged and handled errors professionally
✅ Built a complete real-world application

Your Next Steps#

Short Term#

  • Practice variations of this project
  • Solve coding challenges on platforms like:
    • LeetCode
    • HackerRank
    • CodeChef

Medium Term#

  • Learn advanced C concepts:
    • Linked lists
    • Trees
    • Graphs
    • Algorithms

Long Term#

  • Consider learning:
    • C++
    • Data Structures & Algorithms
    • Systems Programming
    • Embedded Systems

Resources for Continued Learning#

  • Official C Standard: ISO/IEC 9899:2018
  • Books:
    • “The C Programming Language” by Kernighan & Ritchie
    • “C Programming: A Modern Approach” by K.N. King
  • Online Platforms:
    • GeeksforGeeks
    • TutorialsPoint
    • W3Schools
  • Practice Sites:
    • Project Euler
    • Codeforces
    • SPOJ

Final Tips for Success#

  1. Keep Coding - The only way to master programming is practice
  2. Read Others’ Code - Learn from experienced programmers
  3. Debug Systematically - Use tools, not just print statements
  4. Understand, Don’t Memorize - Focus on concepts, not syntax
  5. Build Projects - Apply what you learn to real problems
  6. Share Your Work - Get feedback from others
  7. Stay Curious - Always learn new techniques and languages

Feedback & Support#

If you found this course helpful:

  • Share it with others learning C
  • Practice regularly
  • Come back to review concepts as needed
  • Challenge yourself with harder projects

Summary#

Congratulations on completing this comprehensive 14-day C programming course! You now have a solid foundation in:

  • Core C Programming: Variables, operators, control flow, functions
  • Data Structures: Arrays, strings, pointers, structures
  • Advanced Concepts: Recursion, dynamic memory, file I/O
  • Professional Skills: Debugging, error handling, best practices
  • Real-World Application: Complete project management system

You’re ready to tackle real programming challenges and continue your software development journey!

Keep coding, keep learning, and enjoy the programming journey! 🚀

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