Revision as of 12:10, 6 April 2010

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  function printMonth(int firstDay, int numDays)

// Print a month starting on a friday with 31 days.
// Put this in a file called CalendarPrinter.java
import javax.swing.JOptionPane;

class JavaProggy
{
	public static void main(String args[])
	{
		String strOutput = printMonth(6, 31);

		System.out.println("January 2010:\n");
		System.out.println(strOutput);

		JOptionPane.showMessageDialog(null, strOutput);
	}

	static String printMonth(int firstDay, int numDays)
	{
		int currentCell = 0;    // What cell number are we in.
		int weekNum;            // What week number of the month
		int dayNum;             // What day of the week are we in

		int dayOutput = 0;      // What number to print in the cell

		String strOutput = "";	// Holds our final message

		for (weekNum = 0; weekNum < 6; weekNum++)
		{
			// Loop until we're at sunday OR we don't need to print more days
			for (dayNum = 0; dayNum < 7 && dayOutput + 1 <= numDays; dayNum++)
			{
				currentCell++;                                  // We're working on a new cell
				if (currentCell >= firstDay)                    // Can we start showing days yet?
				{
					dayOutput = currentCell - firstDay + 1; // What day of the month to show
					if (dayOutput < 10)
					{
						strOutput += " " +dayOutput;	// Show that day with prepended space
					}
					else
					{
						strOutput += dayOutput;
					}
					strOutput += " ";			// Space between numbers
				}
				else
				{
					strOutput += "   ";           	        // Output a blank cell
				}
			}

			strOutput += "\n";					// Done drawing a week, start a new line
		}

		return strOutput;
	}
}