Вход и изход
#include <iostream>
using namespace std;
int main()
{
 cout << "How many pennies do you have? ";
 int pennies;
 cin >> pennies;

 cout << "How many nickels do you have? ";
 int nickels;
 cin >> nickels;

 cout << "How many dimes do you have? ";
 int dimes;
 cin >> dimes;

 cout << "How many quarters do you have? ";
 int quarters;
 cin >> quarters;

 double total = pennies * 0.01 + nickels * 0.05 +
                  dimes * 0.10 + quarters * 0.25;
   /* total value of the coins */
 cout << "Total value = " << total << "\n";
 return 0;
}

 cout << "How many nickels do you have? ";
 cin >> count;
 total = count * 0.05 + total;

 cout << "How many dimes do you have? ";
 cin >> count;
 total = count * 0.10 + total;

 cout << "How many quarters do you have? ";
 cin >> count;
 total = count * 0.25 + total;

 cout << "Total value = " << total << "\n";
 return 0;
}
* текуща стойност на променлива
* дефиниция на променлива (единствена !)
-- с инициализация
  double total = count * 0.01;
-- без инициализация
  int count;
* оператор за присвояване
total = count * 0.05 + total;
* знакът за равенство в математиката и в С++
* съкращение за оператора добавяне на 1 и изваждане на 1
 month=month+1   month++
 month=month-1   month--

Константи
#include <iostream>
using namespace std;
int main()
{
 double bottles;
 cout << "How many bottles do you have? ";
 cin >> bottles;

 double cans;
 cout << "How many cans do you have? ";
 cin >> cans;

 double total = bottles * 2 + cans * 0.355;

 cout << "The total volume is " << total << "\n";
 return 0;
}

 double cans;
 cout << "How many cans do you have? ";
 cin >> cans;

 const double BOTTLE_VOLUME = 2.0;
 const double CAN_VOLUME = 0.355;
 double total = bottles*BOTTLE_VOLUME + cans*CAN_VOLUME;

 cout << "The total volume is " << total << " liter.\n";
 return 0;
}

Аритметика