Arrays as Class Member Variables

1. A class can have arrays as member variables.
   
   
2. It is illustrated here in a class called TempertureList, which has an array or a list of temperatures called list as a member variable.
   
   The array will typically be only partially filled and so a second member variable called size is used to specify the actual number of indexed variables of the array that are being used to store values.
   
   
3. //This is the INTERFACE for the class TemperatureList.
   //Values of this type are lists of Fahrenheit temperatures.
   
   #include <iostream>
   #include <cstdlib>
   #include <iomanip>
   using namespace std;
   
   const int MAX_LIST_SIZE = 50;
   
   class TemperatureList
   {
   private:
       double list[MAX_LIST_SIZE]; //of temperatures in Fahrenheit
       int size;             //number of array positions filled
   
   public:
       TemperatureList( );
       //Initializes the object to an empty list.
   
       void add_temperature(double temperature);
       //Precondition: The list is not full.
       //Postcondition: The temperature has been added to the list.
   
       bool full( ) const;
       //Returns true if the list is full. false otherwise.
   
       void display_temperature( ) const;
       //Temperatures are displayed on the screen one per line.
   
   };
   
   //This is the IMPLEMENTATION of the class TemperatureList.
   
   TemperatureList::TemperatureList( )
   {
       size = 0;
   }
   
   //Uses iostream and cstdlib:
   void TemperatureList::add_temperature(double temperature) {
       if ( full( ) )
       {
           cout << "Error: adding to a full list.\n";
           exit(1);
       }
       else
       {
           list[size] = temperature;
           size = size + 1;
       }
   }
   
   bool TemperatureList::full( ) const {
       return (size == MAX_LIST_SIZE);
   }
   
   //Uses iostream:
   void TemperatureList::display_temperature( ) const {
       cout.setf(ios::fixed | ios::showpoint);
       cout.precision(2);
       cout << "This is the list of temperature in Fahrenheit:\n";
   
       for (int i = 0; i < size; i++)
           cout << setw(7) << list[i] << " F\n";
       }
   
   int main ( )
   {
       TemperatureList daily_high;
   
       daily_high.add_temperature(59);
       daily_high.add_temperature(63);
       daily_high.add_temperature(64);
   
       daily_high.display_temperature( );
   
       return 0;
   }