Question

Alright, im trying to understand this,

so a class is simply creating a template for an object.

class Bow
{

int arrows;

};

and an object is simply creating a specific item using the class template.

Bow::Bow(arrows)
{
arrows = 20;
}

also another question, public specifiers are used to make data members avaible in objects and private specifiers are used to make data memebers only avaialble inside the class?

Answer 1

The description you gave is mostly correct but your examples don’t show what you are describing.

A class describes a set of data members and member functions which can be called on those data members:

class Bow
{
public:
   //Constructor
   Bow::Bow()
   {
     arrows = 20;
   }

   Bow::Bow(int a)
   {
     arrows = a;
   }


   //member functions (in this case also called accessors/modifiers)
   void getArrows(int a) const
   {
     return arrows;
   }

   void setArrows(int a)
   {
     arrows = a;
   }

protected:
  int arrows;
  };

And an object of a class is simply an instance of that class.

//b and d are objects of the class Bow.
Bow b(3);//The constructor is automatically called here passing in 3
Bow d(4);//The constructor is automatically called here passing in 4
Bow e;//The constructor with no parameters is called and hence arrows = 20

Note: I purposely avoided the use of the word template that you used because it’s used for something entirely different in C++ than what you meant.

---

To understand public/private/protected specifiers:

public: means that objects of the class can use the members directly.

protected: means that objects of the class cannot use the members directly. Derived classes that are based on that class can use the members.

private: means that objects of the class cannot use the members directly. Derived classes that are based on that class cannot use the members either.

So in the above example:

Bow b(3);
b.arrows = 10;//Compiling error arrows is not public so can't be accessed from an object