Class Coding

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Hi guys..i need some help transforming the following code to class style. i dont have any idea about classes. it's only functional but our prof wants it to be in a class coding. i need help.. here's my code.

#include <iostream.h>
#include <stdlib.h>
 
struct node
  {  char name[20];
     int age;
     int id_num;
     node *nxt;
  };
 
node *start_ptr = NULL;
node *current;
int option = 0;
 
 
void insert_at_end()
  {  node *temp, *temp2;
 
     temp = new node;
     cout << "Please enter the name of the student: ";
     cin >> temp->name;
     cout << "Please enter the age of the student : ";
     cin >> temp->age;
     cout << "Please enter the ID Number of the student : ";
     cin >> temp->id_num;
     temp->nxt = NULL;
 
     if (start_ptr == NULL)
       { start_ptr = temp;
     current = start_ptr;
       }
     else
       { temp2 = start_ptr;
         while (temp2->nxt != NULL)
           {  temp2 = temp2->nxt;
           }
         temp2->nxt = temp;
       }
  }
 
void display_list()
  {  node *temp;
     temp = start_ptr;
     cout << endl;
     if (temp == NULL)
       cout << "The list is empty!" << endl;
     else
       { while (temp != NULL)
       {
          cout << "Name : " << temp->name << " ";
          cout << "Age : " << temp->age << " ";
          cout << "ID Number : " << temp->id_num;
          if (temp == current)
          cout << " \t\t --> Current First Element";
          cout << endl;
          temp = temp->nxt;
       }
     cout << "\nEnd of list!" << endl;
       }
  }
 
void delete_start_node()
   { node *temp;
     temp = start_ptr;
     start_ptr = start_ptr->nxt;
     delete temp;
   }
 
void delete_end_node()
   { node *temp1, *temp2;
     if (start_ptr == NULL)
          cout << "The list is empty!" << endl;
     else
        { temp1 = start_ptr;
          if (temp1->nxt == NULL)
             { delete temp1;
               start_ptr = NULL;
             }
          else
             { while (temp1->nxt != NULL)
                { temp2 = temp1;
                  temp1 = temp1->nxt;
                }
               delete temp1;
               temp2->nxt = NULL;
             }
        }
   }
 
int main() { 
 
 system("CLS");
 start_ptr = NULL;
     do
    {
      display_list();
      cout << endl;
      cout << "1. Add a node to the end of the list." << endl;
      cout << "2. Delete the start node from the list." << endl;
      cout << "3. Delete the end node from the list." << endl;
      cout << "4. Exit application." << endl;
      cout << "\nEnter your choice: ";
      cin >> option;
 
      switch (option)
        {
          case 1 : insert_at_end(); break;
          case 2 : delete_start_node(); break;
          case 3 : delete_end_node(); break;
        }
    }
     while (option != 4);
     cout << endl;
     return 0;
  }

[sicarie]

Okay, have you read about classes? Do you know what would translate well from your program to a class?

PS - you should read up on current C++ standards, you're using the depricated header method (including the .h). I didn't look for it, but you should also make sure you're declaring the proper namespace(s).

[weaknessforcats]

Before you get all caught up in classes, be aware that classes in C++ are implemented as structs. That is, this code:

struct MyStuff
{
     private:
        int data;
     public:
        MyStuff(int arg);   //constrcutor
      ~MyStuff();    //destructor
     int GetData(MyStuff* arg);
};
 

is identical to this code:

class MyStuff
{
     private:
        int data;
     public:
        MyStuff(int arg);   //constrcutor
      ~MyStuff();    //destructor
     int GetData(MyStuff* arg);
};
 

That is, all that changed was the keyword struct to class.

The only difference between a struct and a class is that the default access for a struct is public whereas the default access for a class is private.

So, your problem is already solved. You are already using classes.

All you need to do is move the function prototype of your functions inisde the struct where they become member functions. You should be able to recompile all everythng should still work. A function:

int GetData(MyStuff* arg)
{
 
}
 

becomes:

int MyStuff::GetData(MyStuff* arg)
{
 
}
 

Once your functions are inside the struct, then you can make the data members private. This will cut off any access to those members from anay function that is not a member function.

Once that works, then you can remove the function argument for the address of the struct variable since that address is supplied by the compiler as an invisible first argument for member functions:

struct MyStuff
{
     private:
        int data;
     public:
        MyStuff(int arg);   //constrcutor
      ~MyStuff();    //destructor
     int GetData();   //<<<<<<<<<<no need for MyStuff* argument
};
 

Finally, change the keyword from struct to class. Or, just leave it as a struct. It makes no difference.

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oh i got it..thanks a lot for the help dudes.