Project in c++, making a phonebook

Question

I tried and looked everywhere on the internet, I can't seem to find much.
Now, without too much talking, to the problem I have: I have to make a project for college that consists of making an "electronic phone-book" using OOP programming logic in C++. The materials I`ve received to do this are extremely vague so I must do on my own somehow.

Here is the code I have done so far(with help from the internet):

#include <conio.h>
#include <stdio.h>
#include <stdlib.h>
#include <iostream.h>
#include <string.h>
#include <fstream.h>

void op1()
{
    printf("\n Add contact");
    getch();
}
void op2()
{
    printf("\n Delete contact");
    getch();
}
void op3()
{
    printf("\n Edit a contact");
    getch();
}
void op4()
{
    printf("\n Find a contact");
    getch();
}
void op5()
{
    printf("\n Sort the contacts");
    getch();
}

void op6()
{
    printf("\n 'About the program, details etc. etc.");
    getch();
}



void print_menu()
{
  system("cls");        // clearing window
    printf("\nMenu:");
    printf("\n##############################\n");
  printf("\n1. Add contact");
  printf("\n2. Delete contact");
  printf("\n3. Edit a contact");
  printf("\n4. Find a contact");
  printf("\n5. Sort the contacts");
  printf("\n6. About");
  printf("\n7. Exit");
    printf("\n\n##############################");

  printf("\n\nInput your option: ");
}

// Text centering function - begin
void centerText(char* s)
{
     int l=strlen(s);
     int pos=(int)((80-l)/2);
     for(int i=0;i<pos;i++)
         cout<<" ";
     cout<<s<<endl;
}
// Text centering functon - end

void main()
{

    {   

        printf("\n 'My University' 'My City' ");
        printf("\n Faculty of Electrical Engineer and Computer Science");
        printf("\n Study program used: C++\n\n");
        centerText("C++ Project");
        centerText("<The Phonebook>");
        printf("\n");
        centerText("<my name, Year I of study, Group>");
        printf("\n");
        printf("\n");
        centerText("<june.2013>");
        system("pause>nul"); // Screen is paused until a key is pressed (to allow this text to be viewed)

    }
    // ... Sequence for password verification ...
    {
        char password[20], my_password[20]="2013";
        system("cls");
        printf("WARNING!\n");
        printf("Authentication required!\n");
        printf("\nType input password: ");
        scanf("%19s",password);

            if (strcmp(password, my_password)!=0)
            {

                printf("\n\nIncorrect password !!!\n");
                printf("The program will now exit...\n");
                getch();
                return;
            }

        printf("\n\nPassword is correct !\n");
        printf("The program is executed !\n");
        getch();
    }
  char optiune;

  // ... Sequence for option choosing ...

  do
  {
  print_menu();
  fflush(stdin);
  cin>>optiune;
  switch(optiune)
  {
    case '1':  op1(); break;
    case '2':  op2(); break;
    case '3':  op3(); break;
    case '4':  op4(); break;
    case '5':  op5(); break;
    case '6':  op6(); break;
    case '7':  exit(0);
    default :   printf("\n\nIncorrect option !"); 
                fflush(stdin);
                getch();
  }
  }
  while(1);
}

The idea was that I could maybe use this menu in a way like, just inserting in one of the op() functions the redirect to another file, which is 1 function in a separate file. So I would then have this program as a main program and each function that "adds, edits, deletes ..etc will be outside of this program and I would deal with them separately. Thing is ..I have no clue in doing so. I've looked in the "header" working system and I didn't really find anything of value there. Maybe I don't know to look but trust me I've really tried. Any feedback is much appreciated, but remember I am extremely newbie in this. Please, if you can, explain with as much detail as you can. I appreciate anyone who read this entire thing. I will thank the beginning.

Answer 1

1. You say you can't find help anywhere, but then you say "I have to make a project for college". So presumably you already have instructors and/or professors to help you learn? Other than that, any introductory C++ book ever written will cover what you're asking for, here.

2. You say "using OOP programming logic in C++", yet you don't use any OOP other than built in IO classes.

3. Indent your code properly.

4. Don't use these:

   #include <conio.h>
   
   getch()
   
   system("cls")
   

5. You're mixing calls to printf() with std::cout, and calls to scanf() with std::cin - pick one or the other, and never use scanf().

6. If you're using C++, using std::string is better than this:

   void centerText(char* s)
   

7. The cast here is unnecessary, when you're assigned to an int it'll automatically convert:

   int pos=(int)((80-l)/2);
   

8. main() returns int, don't do this:

   void main()
   

9. You can't fflush(stdin), flushing is not defined on input streams.

10. Don't put things on one line like this, because it looks awful:

    case '1':  op1(); break;
    

11. It's better to return 0 than exit(0) under normal circumstances, as exit(0) will not destroy your objects.

Answer 2

In many applications there are three main components to building the solution. There is the View, which is how you interact with the user. Your work so far looks as though you are building a fairly sensible command line interface for that. Then there is the back end where the contacts will be stored. This could be a file, a database or some kind of JSON or XML structure. In between is the controller that keeps the view and database in sync and executes commands and queries from the user. Maybe this is going too far for your coursework and you are happy if everything is forgotten when you kill the program. In that case you need a memory-based structure to hold the data. I suggest you make a class to hold all the fields in your contact and store in in a std::vector<Contact>.