cardobj.cpp

本课程主要介绍面向对象程序设计的方法和c++语言的基本概念。以c++语言中的面向对象机制为主。学习者在学习过程中可以通过大量的程序实例和相关练习

// cardobj.cpp
// cards as objects
#include <iostream>
using namespace std;

const int jack = 11;          //from 2 to 10 are
const int queen = 12;         //integers without names
const int king = 13;
const int ace = 14;
enum Suit { clubs, diamonds, hearts, spades };
////////////////////////////////////////////////////////////////
class card
   {
   private:
      int number;             //2 to 10, jack, queen, king, ace
      Suit suit;              //clubs, diamonds, hearts, spades
   public:
		card ()                 //constructor (no args)
         {  }
                              //constructor (two args)
      card (int n, Suit s) : number(n), suit(s)  
         {  }
      void display();         //display card
      bool isEqual(card);     //same as another card?
   };
//--------------------------------------------------------------
void card::display()          //display the card
   {
   if( number >= 2 && number <= 10 )
      cout << number << " of ";
   else
      switch(number)
         {
         case jack:  cout << "jack of ";  break;
         case queen: cout << "queen of "; break;
         case king:  cout << "king of ";  break;
         case ace:   cout << "ace of ";   break;
         }
   switch(suit)
      {
      case clubs:    cout << "clubs"; break;
      case diamonds: cout << "diamonds"; break;
      case hearts:   cout << "hearts"; break;
      case spades:   cout << "spades"; break;
      }
   }
//--------------------------------------------------------------
bool card::isEqual(card c2)       //return true if cards equal
   {
   return ( number==c2.number && suit==c2.suit ) ? true : false;
   }
////////////////////////////////////////////////////////////////
int main()
   {
   card temp, chosen, prize;      //define various cards
   int position;

   card card1( 7, clubs );        //define & initialize card1
   cout << "\nCard 1 is the ";
   card1.display();               //display card1

   card card2( jack, hearts );    //define & initialize card2
   cout << "\nCard 2 is the ";
   card2.display();               //display card2

   card card3( ace, spades );     //define & initialize card3
   cout << "\nCard 3 is the ";
   card3.display();               //display card3

   prize = card3;                 //prize is the card to guess

   cout << "\nI'm swapping card 1 and card 3";
   temp = card3; card3 = card1; card1 = temp;

   cout << "\nI'm swapping card 2 and card 3";
   temp = card3; card3 = card2; card2 = temp;

   cout << "\nI'm swapping card 1 and card 2";
   temp = card2; card2 = card1; card1 = temp;

   cout << "\nNow, where (1, 2, or 3) is the ";
   prize.display();               //display prize card
   cout << "? ";
   cin >> position;               //get user's guess of position

   switch (position)
      {                           //set chosen to user's choice
      case 1: chosen = card1; break;
      case 2: chosen = card2; break;
      case 3: chosen = card3; break;
      }
   if( chosen.isEqual(prize) )    //is chosen card the prize?
      cout << "That's right!  You win!";
   else
      cout << "Sorry. You lose.";
   cout << "  You chose the ";
   chosen.display();              //display chosen card
   cout << endl;
   return 0;
   }