list0508.cpp

teach yourself C++ in 21 days 第五版

// Listing 5.8 - demonstrates
// function polymorphism
  
#include <iostream>
  
int Double(int);
long Double(long);
float Double(float);
double Double(double);
  
using namespace std;

int main()
{
   int      myInt = 6500;
   long     myLong = 65000;
   float    myFloat = 6.5F;
   double   myDouble = 6.5e20;
  
   int      doubledInt;
   long     doubledLong;
   float    doubledFloat;
   double   doubledDouble;
  
   cout << "myInt: " << myInt << "\n";
   cout << "myLong: " << myLong << "\n";
   cout << "myFloat: " << myFloat << "\n";
   cout << "myDouble: " << myDouble << "\n";
  
   doubledInt = Double(myInt);
   doubledLong = Double(myLong);
   doubledFloat = Double(myFloat);
   doubledDouble = Double(myDouble);
  
   cout << "doubledInt: " << doubledInt << "\n";
   cout << "doubledLong: " << doubledLong << "\n";
   cout << "doubledFloat: " << doubledFloat << "\n";
   cout << "doubledDouble: " << doubledDouble << "\n";
  
   return 0;
}
  
int Double(int original)
{
   cout << "In Double(int)\n";
   return 2 * original;
}
  
long Double(long original)
{
   cout << "In Double(long)\n";
   return 2 * original;
}
  
float Double(float original)
{
   cout << "In Double(float)\n";
   return 2 * original;
}
  
double Double(double original)
{
   cout << "In Double(double)\n";
   return 2 * original;
}