Question

我是编程新手，所以我不确定问题是什么。我一直在犯的错误在AddTopping(string toppings)。一个是illegal reference to non-static member PizzaOrder::toppings。另一个是'initializing' can not convert for " to std::string.

这就是我现在所拥有的：

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

class PizzaOrder
{
private:
   static const int MAX_SIZE=1000;
   int size;
   string toppings[MAX_SIZE];
   int num_toppings;
public:
   static const string toppings_offered [4];
   static const int DEFAULT_SIZE= 0;
   static const int DEFAULT_TOPPINGS=0;
   static const double topping_base_cost;
   static const double base_price;

   PizzaOrder ();
   PizzaOrder (int size);
   bool SetSize (int size);
   int GetSize () {return size;}
   static string AddTopping (string topping);
   static int AddTopping (int n);
   static double GetPrice ();
   static string StringizeSize ();
   static string GetToppings ();
   static void DisplayPizza();
};
const double PizzaOrder :: topping_base_cost= .5;
const double PizzaOrder :: base_price= 5;
const string PizzaOrder ::toppings_offered[4]={"olives","bell peppers","onions","pepperoni"};
int main ()
{
   PizzaOrder order;
   char pizza_size;
   int topping_choice;

   short array_size = sizeof(order.toppings_offered)/sizeof(order.toppings_offered[0]);



   cout << "Would you like a size [S]small , [M]medium, [L]large pizza or [Q]quit?" <<endl;
   while ( pizza_size != 'Q' || pizza_size != 'q')
   {
      cin >> pizza_size;
      if( pizza_size == 'S' || pizza_size == 's')
         order.SetSize(0);
      if(pizza_size == 'M' || pizza_size == 'm')
         order.SetSize(1);
      if(pizza_size == 'L' || pizza_size == 'l')
         order.SetSize(2);
      while (topping_choice !=0)
      {
         cout << "Current Pizza : " << order.StringizeSize () << order.GetToppings ();
         cout <<"Select an item by number. (Enter 0 when done)" << endl;
         for (int i=0; i< array_size-1; i++)
         {
            cout << (i+1) << ". " << order.toppings_offered[i]<< endl;
         }
         cout << "Selection?";
         cin >>topping_choice;
         order.AddTopping(topping_choice);
      }
   }

         return 0;
}
PizzaOrder::PizzaOrder()
{
   size=DEFAULT_SIZE;
   num_toppings=DEFAULT_TOPPINGS;
}
PizzaOrder::PizzaOrder(int size)
{
   if(!SetSize(size))
      size=DEFAULT_SIZE;
}
bool PizzaOrder::SetSize(int size)
{
   if (size != 0 || size !=1 || size !=2)
      return false;
   this -> size=size;
   return true;
}
string PizzaOrder::AddTopping(string topping)
{
   string temp_toppings[]={toppings};
   short array_size = sizeof(temp_toppings)/sizeof(temp_toppings[0]);
   num_toppings+1;
   toppings[num_toppings];
   for(int k=0; k<array_size-1; k++)
   {
      toppings[k]= num_toppings[k];
   }
   toppings[num_toppings]= topping;

}
int PizzaOrder::AddTopping(int n)
{
   string temp_toppings[]={toppings};
   short array_size = sizeof(temp_toppings)/sizeof(temp_toppings[0]);
   num_toppings+1;
   toppings[num_toppings];
   for(int k=0; k<array_size-1; k++)
   {
      toppings[k]= num_toppings[k];
   }
   toppings[num_toppings]=toppings_offered[n];
}
double PizzaOrder ::GetPrice()
{
   double price;
   double multiplier;
   if(size==0)
      multiplier=1;
   if(size==1)
      multiplier=1.15;
   if (size==2)
      multiplier=1.25;
   price= (base_price*multiplier)+(num_toppings*topping_base_cost);
   return price;
}
string PizzaOrder::StringizeSize()
{
   if(size==0)
      return "small";
   if(size==1)
      return "medium";
   if (size==2)
      return "large";
}
string PizzaOrder::GetToppings()
{
   string temp= "";
   for(int x=0,x<num_toppings-1, x++)
      temp+= "+ " + toppings[x];

   return temp;

}
void PizzaOrder::DisplayPizza()
{
   cout << StringizeSize ()<< GetTopping () << GetPrice ();
}

Answer 1

你有一堆不应该是静态的静态函数，包括AddTopping。阅读静电。

我不完全确定您在“初始化无法转换”错误的哪一行（请在未来的问题中提供完整的错误信息，包括行号），但我打赌这是第一行AddTopping的整数重载。我收集到你正在尝试复制当前“toppings”数组成员的内容（因为你已经将函数声明为static而这是不可访问的 - 这可能是错误消息中缺少类型信息的原因）一个temp_toppings数组。正如你所写的那样，这行不是有效的C ++。我建议你使用谷歌“C ++拷贝阵列”并阅读第一个链接，这是一个很好的阵列教程，位于augustcouncil.com网站上。

Answer 2

即使你摆脱了所有的错误，你也会在while循环中运行一个无限循环 -

我认为这个循环的目的是打破循环。但它永远不会这样 -

while ( pizza_size != 'Q' || pizza_size != 'q')
{
    // .....
}

当pizza_size等于Q且||条件时，条件结果为真且无限循环。它应该是 -

pizza_size ='Q'=＆gt;假|| true =＆gt;是的 - ＆gt; while循环继续
pizza_size ='q'=＆gt;真|| false =＆gt;是的 - ＆gt; while循环继续

while ( (pizza_size != 'Q') && (pizza_size != 'q'))
{
    // .....
}

希望它在以后的阶段有所帮助。

C ++ Pizza Order Program不确定错误发生的原因

2 个答案: