pe7-7.cpp

// pe7-7.cpp -- a modified version of arrfun3 (listing 7.7)
// This is exercise 7 of chapter 7 in C++ Primer Plus by Stephen Prata

#include<iostream>
const int Max = 5;

// function prototypes
double * fill_array(double * ar, int limit);
void show_array(const double * ar, double * end); 	// don't change data
void revalue(double r, double * ar, double * end);

int main(void)
{
	using namespace std; 		
	double properties[Max];
	double * end = fill_array(properties, Max);
	show_array(properties, end);
	cout << "Enter revaluation factor: ";
	double factor;
	cin >> factor;
	revalue(factor, properties, end);
	show_array(properties, end);
	cout << "Done.\n";
	return 0;
}
	
double * fill_array(double * ar, int limit)
{
	using namespace std;
	double temp;
	int i;
	for (i = 0; i < limit; i++)
	{
		cout << "Enter value #" << (i + 1) << ": ";
		cin >> temp;
		if (!cin) 	// bad input
		{
			cin.clear();
			while (cin.get() != '\n')
				continue;
			cout << "Bad input; input process terminated.\n";
			break;
		}
		else if (temp < 0) 	// signal to terminate
			break;
		*(ar + i) = temp;
	}
	return (ar + i);
}

void show_array(const double * ar, double * end)
{
	using namespace std;
	const double * temp = ar;
	for (int i = 0; temp < end; i++, temp++)
	{
		cout << "Property #" << (i + 1) << ": $";
		cout << *temp << endl;
	}
}

// multiplies each element of ar[] by r
void revalue(double r, double * ar, double * end)
{
	double * temp = ar;
	for (int i = 0; temp < end; i++, temp++)
		*temp *= r;
}