在main中调用类函数

Question

I have some class functions outside of the main I want to call back within it and I'm not doing it correctly. The code compiles, but doesn't display anything when run.

#include <iostream>
#include<string>
#include <vector>
using namespace std;

string again;
char pType, pSize, topping, temp;
const int SMALL = 1;
int type = 0, size = 0;
const int MEDIUM = 2;
const int LARGE = 3;
const int DEEPDISH = 1;
const int HANDTOSSED = 2;
const int PAN = 3;
double total = 0;

class Pizza
{
    private:
          int type;
          int size;
          bool cheese;    
          bool pepperoni; 

    public:
          Pizza();
          int getType();
          int getSize();
          bool getCheese();
          bool getPepperoni();
          void setType(int t);
          void setSize(int s);
          void setCheese(bool choice);
          void setPepperoni(bool choice);

  void outputDescription();
  double computePrice();
}; 
class Order
{
private:
    vector<Pizza> c;  
public:
    Order();
    void customerOrder();
    void customerTotal();
    void customerinput();
}; 

The functions

Order custmizedTotal;
Pizza myPizza;  
bool done=false;
void Order::customerinput(){
while ( again == "y"){  
        cout << "What sized pizza, please enter S, M OR L: ";
        cin >> pSize;
        cin.clear();

        switch(pSize)
        {
            case 'S': case 's':
            size = SMALL; break;
            case 'M': case 'm':
            size = MEDIUM; break;
            case 'L': case 'l':
            size = LARGE; break;
        }

        cout << "What type of pizza, enter D for Deepdish, H for Hand tossed, and P for Pan: ";
        cin >> pType;
        cin.clear();

        switch(pType)
        {
            case 'D': case 'd':
            type = DEEPDISH; break;
            case 'H': case 'h':
            type = HANDTOSSED; break;
            case 'P': case 'p':
            type = PAN; break;
        }

        myPizza.setSize(size);
        myPizza.setType(type);

        cout << "Would you like cheese (y/n)? ";
        cin >> topping;
        cin.clear();

        if (topping == 'Y' || topping == 'y')
            myPizza.setCheese(true);

        cout << "Would you like pepperoni (y/n)? ";
        cin >> topping;
        cin.clear();

        if (topping == 'Y' || topping == 'y')
            myPizza.setPepperoni(true);

      cout << endl
       << "Your order: ";
      myPizza.outputDescription();
      cout << endl;
      cout << "Price: $" << myPizza.computePrice() << endl;

      cout << "Again? (y/n)";
      cin >> again;    
    }
        }

Order::Order(){
double total = 0;   
}


void Order::customerTotal(){

    cout << "Your Total order is: " << endl;
    for(int i=0; i<c.size(); i++)
    { 
        c[i].outputDescription();
        cout << endl;
        cout << c[i].computePrice();
        cout << endl;
        total=total+c[i].computePrice();
    }       
    cout << "Totat Cost: $" << total;
    cout << endl;
    c.push_back(myPizza);
}

Main

int main()
{

    custmizedTotal.customerinput();
    if(again != "y"){
    custmizedTotal.customerinput();
    }
    return 0;
}

Answer 1

Here is your code stripped down to a minimal example (this may be the last time anyone does this for you on this site):

#include <iostream>
#include<string>
using namespace std;

int main()
{
  string again;
  while ( again == "y"){
    cout << "taking an order..." << endl;
    cout << "Again? (y/n)";
    cin >> again;
  }

  return 0;
}

Do you see the problem? The variable again is not initialized. The code uses its value before any value has been assigned to it, which is "Undefined Behavior" (which is worse than it sounds), but it's almost certainly not "y", so control never enters the while statement; that code never runs. A better way to do it is like this:

string again;
do{
  cout << "taking an order..." << endl;
  cout << "Again? (y/n)";
  cin >> again;
}while ( again == "y");