// File name:  whiloop.cpp

#include <iostream>
#include <iomanip>
using namespace std;

int main()
{
	int i, sum;

//	i = 0;
//	while (i < 10)
//		cout << setw(3) << i;
//  the above is an endless loop, i never changes, condition always true

	i = 0;
	while (i < 10)
		cout << setw(3) << ++i;
	cout << setw(3) << i << endl;
//  1  2  3  4  5  6  7  8  9 10 10             output from above loop

	i = sum = 0;               // i and sum set to zero
	while (i < 10)
	{
		sum = sum + ++i;
		cout << setw(3) << i << setw(3) << sum;
	}
	cout << setw(3) << i << setw(3) << sum << endl;
//  1  1  2  3  3  6  4 10  5 15  6 21  7 28  8 36  9 45 10 55 10 55  output

	i = 5;
	while (i > 0 && i < 10)    // AND loop - both conditions must be true
		cout << setw(3) << ++i;
	cout << setw(3) << i << endl;
//  6  7  8  9 10 10       output of the above loop

	i = sum = 0;
	while (++i < 4 || sum < 20)  // OR loop - only one condition true
		 cout << setw(3) << i << setw(3) << (sum = sum + i);
	cout << setw(3) << i << setw(3) << sum << endl;
//  1  1  2  3  3  6  4 10  5 15  6 21  7 21

	i = 5;
	do
	{
		++i;
		cout << setw(3) << i;
	} while (i < 5);
	cout << setw(3) << i << endl;
//  6  6   output of the above post-test loop

	i = 0;
	while (++i < 10);
		 cout << setw(3) << i;
	cout << setw(3) << i << endl;
//  10 10    output of the above loop - note semicolon on while statement
    system("pause");
    return 0;
}