srms.cc

#include<iostream>
#include<fstream>
#include<iomanip>
using namespace std;

// the class that stores data
class student
{
    int rollno;
    char name[50];
    int eng_marks, math_marks, sci_marks, lang2_marks, cs_marks;
    double average;
    char grade;
    
    public:
    void getdata();
    void showdata() const;
    void calculate();
    int retrollno() const;
}; 
//class ends here

void student::calculate()
{
    average=(eng_marks+math_marks+sci_marks+lang2_marks+cs_marks)/5.0;
    if(average>=90)
    grade='A';
    else if(average>=75)
    grade='B';
    else if(average>=50)
    grade='C';
    else
    grade='F';
}

void student::getdata()
{
    cout<<"Enter student's roll number: ";
    cin>>rollno;
    
    cout<<"Enter student's name: ";
    cin.ignore();
    cin.getline(name,50);

    cout<<"\n\nEnter Student's Marks"<<endl;
    cout<<"All marks should be out of 100";

    cout<<"\n\nEnter marks in English: ";
    cin>>eng_marks;
    
    cout<<"Enter marks in Math: ";
    cin>>math_marks;

    cout<<"Enter marks in Science: ";
    cin>>sci_marks;
    
    cout<<"Enter marks in Second language: ";
    cin>>lang2_marks;
    
    cout<<"Enter marks in Computer science: ";
    cin>>cs_marks;
    calculate();
}

void student::showdata() const
{
    cout<<"\nRoll number of student : "<<rollno;
    cout<<"\nName of student : "<<name;
    cout<<"\nEnglish : "<<eng_marks;
    cout<<"\nMaths : "<<math_marks;
    cout<<"\nScience : "<<sci_marks;
    cout<<"\nSecond Language : "<<lang2_marks;
    cout<<"\nComputer Science :"<<cs_marks;
    cout<<"\nAverage Marks :"<<average;
    cout<<"\nGrade of student is :"<<grade;
}

int student::retrollno() const
{
return rollno;
}

//function declaration

void create_student();
void display_sp(int);//display particular record
void display_all(); // display all records
void delete_student(int);//delete particular record
void change_student(int);//edit particular record

//Main Function

int main()
{
    char ch;
    cout<<setprecision(2);
    
    do
    {
        char ch;
        int num;
        system("cls");
        cout<<"Welcome to Student Registration Management System"<<endl;
        cout<<"\nMENU"<<endl;
        cout<<"\n1. Create a newstudent record"<<endl;
        cout<<"2. Search student record"<<endl;
        cout<<"3. Display all students records"<<endl;
        cout<<"4. Delete student record"<<endl;
        cout<<"5. Modify student record"<<endl;
        cout<<"6. Exit"<<endl;
        cout<<"\nEnter your choice"<<endl;
        cin>>ch;
        
        system("cls");
        
    switch(ch)
    {
        case '1': create_student(); break;
        case '2': cout<<"\n\n\tEnter The roll number: "; 
        cin>>num;
        display_sp(num); break;
        case '3': display_all(); break;
        case '4':     cout<<"\n\n\tEnter The roll number: ";
        cin>>num;
        delete_student(num);break;
        case '5':     cout<<"\n\n\tEnter The roll number: "; cin>>num;
        change_student(num);break;
        case '6':     cout<<"Exiting, Thank you!";exit(0);
    }
    
    }while(ch!='6');
    return 0;
}

//Write Student Details to File

void create_student()
{
    student stud;
    ofstream oFile;
    oFile.open("student.dat",ios::binary|ios::app);
    stud.getdata();
    oFile.write(reinterpret_cast<char *> (&stud), sizeof(student));
    oFile.close();
    cout<<"\nStudent's record has been created ";
    cin.ignore();
    cin.get();
}

// Read File Records

void display_all()
{
    student stud;
    ifstream inFile;
    inFile.open("student.dat",ios::binary);
    if(!inFile)
{
    cout<<"File could not be opened !! Press any Key to exit";
    cin.ignore();
    cin.get();
    return;
}

cout<<"\n\n\n\t\tDISPLAYING ALL RECORDS\n\n";
while(inFile.read(reinterpret_cast<char *> (&stud), sizeof(student)))
{
    stud.showdata();
    cout<<"\n\n====================================\n";
}

inFile.close();
cin.ignore();
cin.get();
}

//Read Specific Record Based on Roll Number

void display_sp(int n)
{
    student stud;
    ifstream iFile;
    iFile.open("student.dat",ios::binary);
    if(!iFile)
    
    {
        cout<<"File could not be opened... Press any Key to exit";
        cin.ignore();
        cin.get();
        return;
    }
    
    bool flag=false;
    while(iFile.read(reinterpret_cast<char *> (&stud), sizeof(student)))
    {
        if(stud.retrollno()==n)
        {
            stud.showdata();
            flag=true;
        }
    }
    
    iFile.close();
    if(flag==false)
    cout<<"\n\nrecord does not exist";
    cin.ignore();
    cin.get();
}

// Modify Record for Specified Roll Number

void change_student(int n)
{
    bool found=false;
    student stud;
    fstream fl;
    fl.open("student.dat",ios::binary|ios::in|ios::out);
    if(!fl)
    
    {
        cout<<"File could not be opened. Press any Key to exit...";
        cin.ignore();
        cin.get();
        return;
    }
    
    while(!fl.eof() && found==false)
    {
        fl.read(reinterpret_cast<char *> (&stud), sizeof(student));
        if(stud.retrollno()==n)
        {
            stud.showdata();
            cout<<"\nEnter new student details:"<<endl;
            stud.getdata();
            int pos=(-1)*static_cast<int>(sizeof(stud));
            fl.seekp(pos,ios::cur);
            fl.write(reinterpret_cast<char *> (&stud), sizeof(student));
            cout<<"\n\n\t Record Updated";
            found=true;
        }
    }
    
    fl.close();
    if(found==false)
    cout<<"\n\n Record Not Found ";
    cin.ignore();
    cin.get();
}

//Delete Record with Particular Roll Number

void delete_student(int n)
{
    student stud;
    ifstream iFile;
    iFile.open("student.dat",ios::binary);
    if(!iFile)
    {
        cout<<"File could not be opened... Press any Key to exit...";
        cin.ignore();
        cin.get();
        return;
    }
    ofstream oFile;
    oFile.open("Temp.dat",ios::out);
    iFile.seekg(0,ios::beg);
    while(iFile.read(reinterpret_cast<char *> (&stud), sizeof(student)))
    {
        if(stud.retrollno()!=n)
        {
            oFile.write(reinterpret_cast<char *> (&stud), sizeof(student));
        }
    }
    oFile.close();
    iFile.close();
    remove("student.dat");
    rename("Temp.dat","student.dat");
    cout<<"\n\n\tRecord Deleted ..";
    cin.ignore();
    cin.get();
}