linker error caused by class - help needed

i'm working on a small project and i created a class called item that takes two arguments one double and one int,

i've i have a default blank build for that class with no arguments as well where the user can set them if needed.

i'm trying to make an array of them and i'm getting a linker error for unresolved externals

here is a segment of my code.

[code]
class Item
{
public:
// Constructors
Item();
Item(double price, int gramsOfFat);
private:
double price;
int gramsOfFat;
}

void main ()
{
const int MAX_ITEMS = 10;
Item vendingMachine[MAX_ITEMS];
// other stuff
double Price = 0;
int GramsOfFat = 0;
}

I have other code but i think this is the problem, any help would be great.

First of all, it would be helpful to see the exact error message.
Second, you implemented both of your constructors, didn't you?

main.obj : error LNK2019: unresolved external symbol "public: __thiscall Item::Item(void)" (??0Item@@QAE@XZ) referenced in function _main

F:\VendingMachineQuizStudent\Debug\VendingMachineQuiz.exe : fatal error LNK1120: 1 unresolved externals

here is a little more of my code

Code:

---

class Item
{
public:
        // Constructors
        Item();
        Item(double price, int gramsOfFat);

        // Methods
        void setPrice(double pPrice)
        {
                price = pPrice;
        }
        void setGramsOfFat(int pGramsOfFat)
        {
                gramsOfFat= pGramsOfFat;
        }
        double getPrice()
        {
                return price;
        }
        int getGramsOfFat()
        {
                return gramsOfFat;
        }
        double raisePrice(double raisedPrice)
        {
                price += raisedPrice;
        }

private:
        double price;
        int gramsOfFat;
        double raisedPrice;
};


void main()
{
        //constants and classes
        const int MAX_ITEMS = 10;
        Item vendingMachine[MAX_ITEMS];
        // other variables
        double Price = 0;
        int GramsOfFat = 0;
        string textSpacer = "    ";
        string vendStrPrice = "Price";
        string vendStrFatGrams = "Fat Grams";

        srand( (unsigned)time( NULL ) );

        for (int i = 0; i <= MAX_ITEMS; i++)
        {
                vendingMachine[i].setPrice((rand()%175 + 75) / 100);
                vendingMachine[i].setGramsOfFat(rand()%30 + 5);
        }
        cout.setf(ios::showpoint);
        cout.precision(2);
        cout << left << vendStrPrice << textSpacer << vendStrFatGrams << endl;
        for (int i = 0; i <= MAX_ITEMS; i++)
        {
                cout << left << cout << vendingMachine[i].getPrice() << textSpacer
                << vendingMachine[i].getGramsOfFat() << endl;
        }

---

Code:

---

        Item();
        Item(double price, int gramsOfFat);

---

These 2 functions are only declared, not implemented.

Quote:

---

Originally Posted by Skizmo

Code:

---

        Item();
        Item(double price, int gramsOfFat);

---

These 2 functions are only declared, not implemented.

---

down in my main function i have declared my item class as an array, is there a different way to declare this?

Hi,
You need to do this:

Code:

---

Item::Item()
{
}

Item::Item(double price, int gramsOfFat)
{
        m_price = price;
        m_gramsOfFat = gramsOfFat;
}

---

or put this in the class definition.

and then in your class definition you need this:

Code:

---

class Item
{
...........
private:
    double m_price;
    int m_gramsOfFat;
};

---

Notice the "m_" prefix here.

HTH.

Thank you.

Quote:

---

down in my main function i have declared my item class as an array, is there a different way to declare this?

---

What you are doing in the main function has nothing to do with this. You declared 2 constructors, but never implemented the functions itself.

Quote:

---

Originally Posted by Skizmo

What you are doing in the main function has nothing to do with this. You declared 2 constructors, but never implemented the functions itself.

---

cool got it thanks guys,

instead of starting a new topic i'm going to append it to this one if that is okay..

I think i have a logic math error.

i'm trying get a value between 0.75 and 1.75 randomly set i keep getting 2 and 3's and not sure why.

i've set up the line of code as follows

Code:

---

        for (int i = 0; i < MAX_ITEMS; i++)
        {
                vendingMachine[i].setPrice((rand()%175 + 75.0 / 100.0));
                vendingMachine[i].setGramsOfFat(rand()%30 + 5);
        }

---

now if i'm doing this right if the cap is 175 on the random number then i'm adding 75 to it incase it is 0.

i keep getting odd results even numbers like 1.3e+002

i have placed in a 2 point precision and later cout the results i think i may be messing something up or overlooked something.

Quote:

---

Originally Posted by turlisk

cool got it thanks guys,

instead of starting a new topic i'm going to append it to this one if that is okay..

I think i have a logic math error.

i'm trying get a value between 0.75 and 1.75 randomly set i keep getting 2 and 3's and not sure why.

---

1) Generate a random number between 0 and 100.

2) add 75 to 1).

3) divide 2) by 100.

Regards,

Paul McKenzie

thanks guys got it all figured out now.