//             Illustrate several C++ loops      v. 3/29/06

#include <iostream.h> // for cin and cout

int main ()
{
	double sum = 0, value;

	// example using for loop
	int counter;
        sum = 0;
	for( counter=0; counter<10; counter++ ) {
		cin >> value;
		sum += value;
	}

	cout << "Sum 1 is " << sum << endl;

	// again, but this time, use while
        sum = 0;
	counter = 0;
	while( counter<10 ) {
		cin >> value;
		sum += value;

		counter++;
	}

	cout << "Sum 2 is " << sum << endl;

	// example with if statement (say, to check input)
	sum = 0;
	for( counter=1; counter<=10; counter++ ){
		cin >> value;
		while ( value<=0 ) // why not an if?
		{
			cout << "Please enter a positive value" << endl;
			cin >> value;
		}
		sum += value;
	}

	cout << "Sum 3 is " << sum << endl;

	// Example with trip value (to signal end of input)
	sum = 0;
	cin >> value;
	while ( value != -1 ) {
	  sum += value;
	  cin >> value;
	}
	cout << "Sum 4 is " << sum << endl;

	return 0;

}