Class inter-dependence problems - c++

Question

Hey so I have three 2 classes: Screen, and Sprite : that depend on each other so if i define one i can not implement the second class to be defined into it as it has not been definded yet! Is there any simple solution to this that does not require a lot of re-coding?
Heres each class definition (Map is also a class):
the Sprite Class: move() wont work without the Screen Class definition....
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//////////////////////////// Sprite Class ///////////////////////////////////////////////////////////////////////////////////////////////////////////////
class Sprite
{
public:
///////////////////// Get and SET all the privates ///////
Sprite(){};
Sprite(string a_name, char a_symbol, float a_health){
_name = a_name;
_symbol = a_symbol;
_health = a_health;};
char get_symbol() {return _symbol;};
void set_symbol(char _sym) {_symbol = _sym;};
float get_health() {return _health;};
void set_health(float _numb) {_health = _numb;};
void add_health (float _numb) {_health += _numb;};
string get_name() {return _name;};
string set_name(string _aName) {_name = _aName;};
int* get_location(){return _location;};
void set_location(int X, int Y) {
_location[0] = X;
_location[1] = Y;};
//////////////////////////////// Move ////////////
// WONT WORK UNTIL UNLESS SCEEN CLASS IS DEFINED BEFORE IT
bool move(Screen screen,int X, int Y)
{
bool OK = true;
////////////////////// check whats already there /////
char newLoc = screen.get_contents(_location[1]+Y,_location[0]+X);
if (newLoc == '|' || '/' || '_' || '=' || 'X' || 'x' )
OK = false;
if (OK == true)
{
_location[0] += X;
_location[1] += Y;
return true;
}
else
return false;
};
private:
string _name;
char _symbol;
float _health;
int _location[2];
};
And the screen class: (the sprite overloaded insert function won't work without Sprite def.
///////////////////////// SCREEN CLASS ///////////////////////////////////////////////////////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
class Screen
{
private:
/////////////////////////////////////////// Screen Variables ///////////////
string _name;
vector <string> _contents;
public:
Screen(string name){_name = name;
_contents.resize(24);};
~Screen(){};
//////////////////////////////////////////// Get contents ///////////////////////////
string get_contents(int Y) {return _contents[Y];};
char get_contents(int X, int Y) {return _contents[Y][X];};
//////////////////////////////////////////// Display (1 FPS) ///////////////////////////
void Display(int numbRefreshes) //
{ //
for(int t = 0; numbRefreshes > t;) //
{ //
UL_2 = GetTickCount()+overSec-UL_1; // Get Time in Milliseconds since start //
// GATE TO GETTING INTO THE DISPLAY FUNCTION (every 1 sec)
if (UL_2 >= 1000) //
{ //
overSec += 1000 - UL_2; //
// Wait another second before update (1000 milliseconds) //
UL_1+=1000; //
UL_3+= 1; //
char UL_3_string[6]; //
itoa(UL_3, UL_3_string, 10); //
// Tell the for loop 1 render is complete (/////)
t+=1; // (///)
// Update the time counter (/)
int B = sizeof(UL_3_string); // |
for(int I = 0; I < sizeof(UL_3_string); I++)
Screen::Insert(UL_3_string[I], 38+I, 22);
/////////////////// Draw each line of the Screen
for (unsigned int I = 0; I < _contents.size(); I++)
{
cout << _contents[I];
}
//////////////// draw any empty lines NOT WORKING WTF???????
for(int emptyLines = 24-_contents.size(); emptyLines > 0; emptyLines--)
{
cout << endl;
}
}
}
};
/////////////////////////////////////////// Insert ////////////////////////
/////////////////// map
bool Insert(Map& _map)
{
for (unsigned int I = 0; I<_map.getContents().size();I++)
{
_contents[I] = _map.getContents()[I];
}
return true;
};
/////////////////// string
bool Insert(string _string, int Y)
{
_contents[Y] = _string;
return true;
};
///////////////////// char
bool Insert(char _char, int X, int Y)
{
_contents[Y][X] = _char;
return true;
};
//////////////////// sprite
bool Insert(Sprite& _sprite)
{
_contents[_sprite.get_location()[0]][_sprite.get_location()[1]] = _sprite.get_symbol();
};
};
Screen theScreen("theScreen");
Thanks for any help!! =)

Answer 1

I would redesign - I can't see why a sprite needs to know about a screen. And what is this:
if (newLoc == '|' || '/' || '_' || '=' || 'X' || 'x' )
supposed to be doing? That is not how you test things in C++.
Other problems - don't pass strings by value, pass them as const references, and don't begin names with underscores.

Answer 2

First, split your classes to .h files and .cpp files, then use forward declaration (google for it, I can't post link). There are a few other errors in your code, you might like Bjarne Stroustrup's book "Language c++"