Classes I/O

Pages: 12

Our homework is to write to program one that will out put to a txt file and the other to read from a file. I can get my first program to write to file but I can not get my second file to read from the txt file. I will post them both here if anyone has any idea how to correct this issue that would be wonderful....
Here is my write file

class student
{
    protected:
    
  
      int id;
      string fname;
      string lname;
      float gpa;
      float hours;
      float fees;
      
      
   public:
      student();
      string getfname();
      string getlname();
      float getgpa();
      float getfees();
      float gethours();
      int   getid();
     
      
  
      void setid(int);
      void setgpa(float);
      void setfees(float);
      void sethours(float);      
      void setfname(string);
      void setlname(string);
      
     virtual void display()=0;
     virtual void input()=0;
     virtual void read_to_file(ifstream& filein)=0;
     virtual void write_to_file(ofstream& fout)=0;
     
  };
//*****BASE CLASS MEMBERS****
         
student::student() 
         {
         setlname("");
         setfname("");
         }
         
         int student::getid()
         {return id;}
         
         string student::getfname()
         {return fname;}
         
         string student::getlname()
         {return lname;}
         
         float student::getgpa()
         {return gpa;}
         
         float student::gethours()
         {return hours;}
         
         float student::getfees()
         {return fees;}
                  
         void student::setid(int i)
         {id=i;}
         
         void student::setfname(string n)
         {fname=n;}
         
         void student::setlname(string l)
         {lname=l;}
         
         void student::setgpa(float g)
         {gpa=g;}
         
         void  student::sethours(float h)
         {hours=h;}
         
         
         void student::setfees(float f)
         {fees=f;}
         
       
         
         
       
       
//*****UDERGRAD CLASS****** 
      class Undergrad: public student
      {
      private:
              string lvl;
              bool FA;
              string housing;
              
      public:
      
      bool getFA();
      string getlvl();
      string gethousing();
      void setlvl();     
      void sethousing();      
      void Undergrad::setFA(bool);
      void Undergrad::input();
      void Undergrad::display();
      void read_to_file(ifstream& filein);
      void write_to_file(ofstream& fout);
};
      
      
//*******UNDERGRAD MEMBERS*********
      
      bool Undergrad::getFA()
      {return FA;}  
      
      string Undergrad::getlvl()
      {return lvl;}
      
      string Undergrad::gethousing()   
      {return housing;}                                 
                                           
      void Undergrad::setlvl( )
      {int selection;
     
       cout << "Please Choose Student Year" << endl;
       cout << "1.Freshman 2.Sophomore 3.Junior 4.Senior" << endl;
           cin>>selection;
           switch (selection)
           {
           case 1: lvl="Freshman";
           break;
           case 2: lvl="Sophomore";
           break;
           case 3: lvl="Junior";
           break;
           case 4: lvl="Senior";
           break;
           default: cout<<"Please enter a correct value";
           }
           
       
       
           }
                 
     void Undergrad::sethousing( )
      {int selection;
      cout << "Please Enter Housing Type:"<< endl;
      cout << "1.Dorm 2.Fraternity 3. Sorority" << endl;
           cin>>selection;
           switch (selection)
           {
           case 1: housing="Dorm";
           break;
           case 2: housing="Fraternity";
           break;
           case 3: housing="Sorority";
           break;
           
           default: cout<<"Please enter a correct value";
           }
       
      }
         
      void Undergrad::setFA(bool)
      {int tempFA;
          cout << "Does student have financial aid?" << endl;
          cout << "Please Enter: 1 for Yes or 0 for No.\n" <<endl;
         cin>>tempFA;
       
        if(tempFA==1)
        {FA=true;}
        if(tempFA==0)
        {FA=false;}
       }
        
void Undergrad::input()
{string fname, lname, housing, lvl; int id; float gpa, hours, fees; int FA;
     cout<<"Enter first and last name: ";
     cin>>fname>>lname;
     setfname(fname); setlname(lname);
     cout<<"Enter id number:\n ";
     cin>>id;
     setid(id);
     cout<<"Enter GPA:\n ";
     cin>>gpa;
     setgpa(gpa);
     cout<<"Enter hours:\n ";
     cin>>hours;
     sethours(hours);
     sethousing();
     setlvl();
     setFA(FA);
     Undergrad::display();
     
}     
        
void Undergrad::display()
{float fees;
fees=125*gethours()+185;
cout<< "\nStudent Fees:\n" <<  fees;
    
}
 


  class grad:public student
      {
      private: bool TA; // Teaching Assistend
               string TT; //thesis topic
      public:
               void setTA(bool);
               void setTT();
               bool getTA();
               string getTT();
               void input();
               void display();    
               void read_to_file(ifstream& filein);
               void write_to_file(ofstream& fout);
               
           };
      

bool grad::getTA()
{return TA;}

string grad::getTT()
{return TT;}

void grad::setTA(bool)
{
 bool tempTA;
 cout << "Is Student Teaching Assident?" << endl;
 cout << "1.Yes 0.No" << endl;
 
 cin >> tempTA;
   if (tempTA==1)
    {TA=true;}
   if(tempTA==0)
    {TA=false;}
   

   
}
void grad::setTT()
{
     cout << "Please Enter Graduates Thesis Topic" << endl;
     cin >> TT;

}
void grad::input()
{string fname, lname; int id; float gpa,hours,fees; int TA; string TT;
     cout<<"Enter First and Last name: ";
     cin>>fname>>lname;
     setfname(fname); setlname(lname);
     cout<<"Enter ID number: ";
     cin>>id;
     setid(id);
     cout<<"Enter GPA: ";
     cin>>gpa;
     setgpa(gpa);
     cout<<"Enter hours: ";
     cin>>hours;
     sethours(hours);
     setTA(TA);
     setTT();
     grad::display();
}     
        
void grad::display()
{float fees;
(fees=200*gethours()+275);
cout<< "\nStudent Fees:\n" <<  fees; 

  
}


int main()
{
    
    
    
     ifstream filein;
     filein.open("Undergrad.txt", ios::app);
     filein.open("grad.txt",ios::app);
     ofstream fout;
     
    int Q=1;
    int type;
    student*sPtr;
      
      
    unsigned long n=1;
  do{
      cout << "\n";
      cout << "\nWould you like to create a New Student?" << endl;
      cout <<"\nEnter 1. for Graduate and 2. for Undergrad:\n" << endl;
      cout << "\nEnter 5 to Quit\n";
      cin >> type;
      

      if(type==1)
      {sPtr=new grad;}
      else if(type==2)
      {sPtr=new Undergrad;}
      else if(type==5)
      {cout<<"Program Closing"; n=0;}
      else
         {
          cout << "\nComputer will now Self destruct\n";
          system("pause");
          n=0;
         }
      
      {
        if((type==1)||(type==2))
       { sPtr -> input();
       sPtr -> write_to_file(fout);
        delete sPtr;
        }
        }
          

        
   } while (n != 0);
   
   filein.close();
   

getchar();   
cin.clear();
return 0;
}



//****I/0****
void Undergrad::write_to_file(ofstream& fout)
{
    
fout.open("Undergrad.txt", ios::app);
fout<< getfname()<< getlname()<< getid()<< getgpa() << getlvl()<< gethousing()<< getfees() << endl;
fout.close();      
}    

void grad::write_to_file(ofstream& fout)
{
fout.open("grad.txt", ios::app);
fout << getfname()<< getlname()<< getid()<< gethours()<< getfees()<< getTA()<< getTT()<< endl;
fout.close();
}
void Undergrad::read_to_file(ifstream& filein)
{
string stType;

filein >>  stType >> fname>> lname>> id >> gpa>> lvl>> hours >> housing >> fees;

/*cout<<" "<<fname()<<" "lname()<<" "<< id() << " "<<gpa << " " <<lvl <<" " << hours
<< " "<<housing<<" "<<fees<<endl;}*/}

void grad::read_to_file(ifstream& filein)
{
string stType;
filein >> stType >> fname >> lname >>id >> gpa >> hours >> fees >> TA >> TT; 

/*cout<<" "<< fname()<<" "<< lname()<<" " << id()<<" "<<gpa<<" "<< hours()<<" "<< fees()<<" " << getTA()
<<" "<< TT()<< endl;*/
}

Last edited on

IsisV33 (16)

Here is my read file


int main()
{
ifstream filein;
filein.open("Undergrad.txt", ios::in);
filein.open("grad.txt",ios::in);
ofstream fout;
   
student*sPtr;  
int Q=1;
int type;
char a,b;
 

      
unsigned long n=1;
while(a>b);
{
      cout << "\n";
      cout << "\nPlease enter the file you would like to view:" << endl;
      cout <<"\nEnter 1. for Graduate and 2. for Undergrad:\n" << endl;
      cout << "\nEnter 5 to Quit\n";
      cin >> type;
     
if(type==1)
     {filein.open("grad.txt",ios::in);
     while(filein.eof() == false)
    {sPtr = new grad;      
     sPtr -> read_to_file(filein);
     delete sPtr;
     getchar();
     filein.close();}}
     
else if(type==2)   
{filein.open("Undergrad.txt", ios::in);
     while(filein.eof() == false)
     {sPtr = new Undergrad;      
      sPtr -> read_to_file(filein);
      delete sPtr;
      getchar();
      filein.close();}}
     
else if(type==5)
{cout<<"Program Closing"; n=0;}
else
         {
          cout << "\nComputer will now Self destruct\n";
          system("pause");
          n=0;
         }
      
      {
        if((type==1)||(type==2))
       { sPtr -> input();
       sPtr -> read_to_file(filein);
        delete sPtr;
        }
        }
          

        
   } while (n != 0);
   
   filein.close();

getchar();   
cin.clear();
return 0;
}

Last edited on

Mythios (1058)

At the very least put your code inside [code]code here[/code] tags.

Albatross (4553)

Once you put your code in [code] tags, I'll answer your question.

Nah, just kidding... but please put your code in [code] tags.

~~The functions you defined as virtual need to be not defined as virtual.~~ Yes, they do, but they need not be redeclared in a derived class.

Also, earlier, within your declarations for your Undergrad class, you have a few functions with Undergrad:: stitched on inside the class block. Axe 'em!

-Albatross

Last edited on

m4ster r0shi (2201)

I see here that you output the data for grad students in the file like this:

fout << getfname()<< getlname()<< getid()<< gethours()<< getfees()<< getTA()<< getTT()<< endl;

This really isn't the way to go as you don't have something to separate the elements you output from one another... Try doing it like this:

1
2
3

fout << getfname() << endl << getlname() << endl;
fout << getid() << endl << gethours() << endl << getfees() << endl;
fout << getTA()<< endl <<  getTT()<< endl;

That is output each element in a different line. Now, I don't think it's hard to figure out a way to get them back...

Also the undergrad student file i/o needs to be fixed.

Last edited on

IsisV33 (16)

ok I can see the fout problem now. But the virtual has to be defines that way its part of the assignment that is the only reason it is written like that... Thank I fixed some of the problems but still not working on the read file from txt...
Thank you I will keep working on it..

Albatross (4553)

I edited my above post. The virtuality of those functions is fine, just don't redeclare a virtual function in your child class Undergrad.

-Albatross

IsisV33 (16)

here the read file I am having a problem with the write to file works and writes to the txt..

int main()
{
ifstream filein;
filein.open("Undergrad.txt", ios::in);
filein.open("grad.txt",ios::in);
ofstream fout;
   
student*sPtr;  
int Q=1;
int type;
char a,b;
 

      
unsigned long n=1;
while(a>b);
{
      cout << "\n";
      cout << "\nPlease enter the file you would like to view:" << endl;
      cout <<"\nEnter 1. for Graduate and 2. for Undergrad:\n" << endl;
      cout << "\nEnter 5 to Quit\n";
      cin >> type;
     
if(type==1)
     {filein.open("grad.txt",ios::in);
     while(filein.eof() == false)
    {sPtr = new grad;      
     sPtr -> read_to_file(filein);
     delete sPtr;
     getchar();
     filein.close();}}
     
else if(type==2)   
{filein.open("Undergrad", ios::in);
     while(filein.eof() == false)
     {sPtr = new Undergrad;      
      sPtr -> read_to_file(filein);
      delete sPtr;
      getchar();
      filein.close();}}
     
else if(type==5)
{cout<<"Program Closing"; n=0;}
else
         {
          cout << "\nComputer will now Self destruct\n";
          system("pause");
          n=0;
         }
      
      {
        if((type==1)||(type==2))
       { sPtr -> input();
       sPtr -> read_to_file(filein);
        delete sPtr;
        }
        }
          

        
   } while (n != 0);
   
   filein.close();

getchar();   
cin.clear();
return 0;
}

Albatross (4553)

Yes! It looks so much better!

filein.open("Undergrad",ios::in)
@Line 34

Are you sure that's what you wanted?

-Albatross

Last edited on

IsisV33 (16)

This part of the file works
fout << getfname()<< getlname()<< getid()<< gethours()<< getfees()<< getTA()<< getTT()<< endl;

IsisV33 (16)

At this point I'm not sure what I want if you have any suggestion I'm all ears.

filein.open("Undergrad",ios::in)

IsisV33 (16)

LOL ok I see it need to be Undergrad.txt

Albatross (4553)

~~I know. However, you're opening a file that shouldn't have anything in it. fout writes to "Undergrad.txt".~~

You saw.

-Albatross

Last edited on

IsisV33 (16)

this is the error I am getting [Linker error] undefined reference to `vtable for student'

Albatross (4553)

Wait a minute... I knew something was off, and it's so obvious...

How and when did you define the class "student" in your read file, along with all the child classes and functions?

-Albatross

Last edited on

IsisV33 (16)

this is how the student file and child classes are done.

class student
{
    protected:
    
  
      int id;
      string fname;
      string lname;
      float gpa;
      float hours;
      float fees;
      
      
   public:
      student();
      string getfname();
      string getlname();
      float getgpa();
      float getfees();
      float gethours();
      int   getid();
      
      
  
      void setid(int);
      void setgpa(float);
      void setfees(float);
      void sethours(float);      
      void setfname(string);
      void setlname(string);
      
     virtual void display();
     virtual void input()=0;
     virtual void read_to_file(ifstream& filein)=0;
     virtual void write_to_file(ofstream& fout)=0;
     
  };
//****************BASE CLASS MEMBERS**************************************
         
student::student() 
         {
         setlname("");
         setfname("");
         }
         
         int student::getid()
         {return id;}
         
         string student::getfname()
         {return fname;}
         
         string student::getlname()
         {return lname;}
         
         float student::getgpa()
         {return gpa;}
         
         float student::gethours()
         {return hours;}
         
         float student::getfees()
         {return fees;}
                  
         void student::setid(int i)
         {id=i;}
         
         void student::setfname(string n)
         {fname=n;}
         
         void student::setlname(string l)
         {lname=l;}
         
         void student::setgpa(float g)
         {gpa=g;}
         
         void  student::sethours(float h)
         {hours=h;}
         
         
         void student::setfees(float f)
         {fees=f;}
         
       
         
         
       
       
//*******************UDERGRAD CLASS******************************  
      class Undergrad: public student
      {
      private:
              string lvl;
              bool FA;
              string housing;
              
      public:
      
      bool getFA();
      string getlvl();
      string gethousing();
      void setlvl();     
      void sethousing();      
      void Undergrad::setFA(bool);
      void Undergrad::input();
      void Undergrad::display();
      void read_to_file(ifstream& filein);
      void write_to_file(ofstream& fout);
};
      
      
//************UNDERGRAD MEMBERS*******************************
      
      bool Undergrad::getFA()
      {return FA;}  
      
      string Undergrad::getlvl()
      {return lvl;}
      
      string Undergrad::gethousing()   
      {return housing;}                                 
                                           
      void Undergrad::setlvl( )
      {int selection;
     
       cout << "Please Choose Student Year\n" << endl;
       cout << "1.Freshman 2.Sophomore 3.Junior 4.Senior\n" << endl;
           cin>>selection;
           switch (selection)
           {
           case 1: lvl="Freshman\n";
           break;
           case 2: lvl="Sophomore\n";
           break;
           case 3: lvl="Junior\n";
           break;
           case 4: lvl="Senior\n";
           break;
           default: cout<<"\nPlease enter a correct value\n";
           }
           
       
       
           }
                 
     void Undergrad::sethousing( )
      {int selection;
      cout << "Please Enter Housing Type:"<< endl;
      cout << "1.Dorm 2.Fraternity 3. Sorority" << endl;
           cin>>selection;
           switch (selection)
           {
           case 1: housing="Dorm\n";
           break;
           case 2: housing="Fraternity\n";
           break;
           case 3: housing="Sorority\n";
           break;
           
           default: cout<<"Please enter a correct value";
           }
       
      }
         
      void Undergrad::setFA(bool)
      {int tempFA;
          cout << "Does student have financial aid?" << endl;
          cout << "Please Enter: 1 for Yes or 0 for No.\n" <<endl;
         cin>>tempFA;
       
        if(tempFA==1)
        {FA=true;}
        if(tempFA==0)
        {FA=false;}
       }
        
void Undergrad::input()
{string fname, lname, housing, lvl; int id; float gpa, hours; int FA;
     cout<<"Enter First and Last name: ";
     cin>>fname>>lname;
     setfname(fname); setlname(lname);
     cout<<"Enter id number: ";
     cin>>id;
     setid(id);
     cout<<"Enter GPA: ";
     cin>>gpa;
     setgpa(gpa);
     cout<<"Enter hours: ";
     cin>>hours;
     sethours(hours);
     sethousing();
     setlvl();
     setFA(FA);
     Undergrad::display();
     
}     
        
void Undergrad::display()
{float fees;
fees=125*gethours()+185;
cout<< "\nStudent Fees:\n" <<  fees;
    
}
 

//************************************************
  class grad: public student
      {
      private: bool TA; // Teaching Assistend
               string TT; //thesis topic
      public:
               void setTA(bool);
               void setTT();
               bool getTA();
               string getTT();
               void input();
               void display();    
               void read_to_file(ifstream& filein);
               void write_to_file(ofstream& fout);
               
           };
      
           
//****************GRAD MEMBER***************************************
bool grad::getTA()
{return TA;}

string grad::getTT()
{return TT;}

void grad::setTA(bool)
{
 bool tempTA;
 cout << "Is Student Teaching Assident?" << endl;
 cout << "1.Yes 0.No" << endl;
 
 cin >> tempTA;
   if (tempTA==1)
    {TA=true;}
   if(tempTA==0)
    {TA=false;}
   

   
}
void grad::setTT()
{
     cout << "Please Enter Graduates Thesis Topic" << endl;
     cin >> TT;

}
void grad::input()
{string fname, lname; int id; float gpa,hours; int TA; string TT;
     cout<<"Enter First and Last name: ";
     cin>>fname>>lname;
     setfname(fname); setlname(lname);
     cout<<"Enter ID number: ";
     cin>>id;
     setid(id);
     cout<<"Enter GPA: ";
     cin>>gpa;
     setgpa(gpa);
     cout<<"Enter hours: ";
     cin>>hours;
     sethours(hours);
     setTA(TA);
     setTT();
     grad::display();
}       
        
void grad::display()
{float gfees, setfees;
(fees=200*gethours()+275);
cout<< "\nStudent Fees:\n" <<  fees; 
}

//***************SEPARATE THIS RIGHT HERE******************************
void Undergrad::read_to_file(ifstream& filein)
{
string stType;
filein >>  stType >> fname>> lname>> id >> gpa>> lvl>> hours >> housing >> fees;

//cout<<" "<<fname()<<" "<<lname()<<" "<< id()<< " "<<gpa << " "<<lvl<<" " << hours<<" "<<
//housing<<" "<<fees<<endl;
}

void grad::read_to_file(ifstream& filein)
{
string stType;
filein >> stType >> fname >> lname >>id >> gpa >> hours >> fees >> TA >> TT; 

//cout<<" "<< fname()<<" "<< lname()<<" " << id()<<" "<< 
//<<gpa<<" "<< hours()<<" "<< fees()<<" " << getTA()<<" "<< TT()<<endl;
}
void Undergrad::write_to_file(ofstream& fout)
{
    
fout.open("Undergrad.txt", ios::app);
fout<< getfname()<< getlname()<< getid()<< getgpa() << getlvl()<< gethousing()<< getfees() << endl;
fout.close();      
}    

void grad::write_to_file(ofstream& fout)
{
fout.open("grad.txt", ios::app);
fout << getfname()<< getlname()<< getid()<< gethours()<< getfees()<< getTA()<< getTT()<< endl;
fout.close();
}

IsisV33 (16)

Ok I got all the problems with the writing file fixed now I just need to get the read file to read the txt..

IsisV33 (16)

Is there and easier way I can just write a small read txt file for just reading the txt? I know how to do it In C but not in C++..

Albatross (4553)

Between the two of us, I prefer stdio.h over iostream for most operations. If you do too, use it. Anything you write in C will compile in C++.

-Albatross

IsisV33 (16)

It has to be C++ for my class :(

Pages: 12