Thread: need some help please

Need help changing a stored variable inside a string:
Both parts of the code are on here but if you want to see with syntax colouring i have uploaded onto codepad
Click here for code with syntax highlights
Here are the variables so it isnt confusing:

Code:

string UserName;
string PlayerInv = "\nInventory:";
string ARROW = "\nArrows x";
stringstream ss;
int Money;
int PlayerHP = 75;
int Foodx = 0;
int Drinkx = 0;
int arrowx = 0;
bool arrow_owned = false;
enum ShopMisc{Arrow = 2, Food = 10, Drink = 10,WeaponPoison = 35,} //Ignore all but arrow

What i want to do is that if the user chooses to buy arrows and they already have some in there inventory [arrow_owned == true] instead of when they buy more i dont want it to say this in the inventory
Example:
Inventory:
Food
weapon poison
Arrow x10 <<<<
Arrow x23 <<<<
Bow

instead when they are already owned i want the variable 'arrowx' to be changed by arrowchoice[how many more the user chooses to buy]
ive been stuck with it for AGEESSSS so decided to join this forum in search of help :S
Here is the main part of code im stuck with:

Code:

case 1:
                 {
                   cout << "How many Arrows would you like? :";
                   cin >> arrowchoice;
                   Sleep(1000);
                   cout << "\nYou have chose "<<arrowchoice<< "  Arrows costing " <<(Arrow*arrowchoice)<<" Gold peices\n";
                   if(Money - (Arrow*arrowchoice) >= 0)
                   {
                            if(arrow_owned == true)
                            {                                                           //just a guess so its obv wrong
                                ss >> PlayerInv >> ARROW >> arrowx;
                                Money = (Money - (Arrow*arrowchoice));
                                cout << "You now have: " << Money << " Gold peices\n";
                                arrowx = (arrowx + arrowchoice);
                                ss << PlayerInv << ARROW << arrowx;
                                PlayerInv = ss.str();
                                goto SHOPEND;
                            }                 
                   Money = (Money - (Arrow*arrowchoice));
                   cout << "You now have: " << Money << " Gold peices\n";
                   arrowx = (arrowx + arrowchoice);
                   ss <<PlayerInv << ARROW << arrowx;
                   PlayerInv = ss.str();      
                   arrow_owned = true;
                   goto SHOPEND;
                   }
                   else
                   {
                   cout << "You dont have enough gold for "<< arrowchoice << "arrows\n";
                   goto SHOPEND;                  
                   }
                 }

All works fine apart from the part if(arrow_owned==true){}
it charges for more than 1 and doesnt increase the amount owned

any help ?

Noo, im not trying to get it to just output it.. i could do that
im trying to Get the variable into the string which i can do using string stream
But if arrows are bought twice
for example
first time 10 arrows are bought
second time 30 arrows are bought it will say:

Inventory:
Arrows x 10
Arrows x 30

instead of what i want which is for them to stack up:
Inventory:
Arrows x 40

Oh well, forgive me for being thick.

When you push stuff onto a string stream the data gets tacked to the end. Likewise, if you also pull data from the string stream, it doesn't disappear, the position marker only moves. When you use the same stream to do both of these things it can be confusing.

C++ makes it possible to refresh your stream in a pretty unintuitive way.

Code:

ss >> PlayerInv >> ARROW >> arrowx; // pull the initial state
// buy more arrows here
ss.str(string()); // the refresh
ss << PlayerInv << ARROW << arrowx; // push the current state

You can only replace the internal buffer. I admit that wasn't obvious to me, and I had to look it up.