fig07_03.cpp

来自「经典vc教程的例子程序」· C++ 代码 · 共 47 行

// Fig. 7.3: fig07_03.cpp
// Attempting to initialize a constant of
// a built-in data type with an assignment.
#include <iostream.h>

class Increment {
public:
   Increment( int c = 0, int i = 1 );
   void addIncrement() { count += increment; }
   void print() const;
private:
   int count;
   const int increment;
};

// Constructor for class Increment
Increment::Increment( int c, int i )
{             // Constant member 'increment' is not initialized
   count = c;
   increment = i;  // ERROR: Cannot modify a const object
}

// Print the data
void Increment::print() const
{
   cout << "count = " << count
        << ", increment = " << increment << endl;
}

int main()
{
   Increment value( 10, 5 );

   cout << "Before incrementing: ";
   value.print();

   for ( int j = 0; j < 3; j++ ) {
      value.addIncrement();
      cout << "After increment " << j << ": ";
      value.print();
   }

   return 0;
}