/**
 * This class demonstrates an clear and simple use of comments
 * with a single method that displays primes.
 * @author bederson
 */
public class CommentsGood {
	/**
	 * displayPrimes prints the prime numbers between 2 and the parameter
	 * @param maxNumber The largest possible prime number to display
	 */
	public void displayPrimes(int maxNumber) {
		int[] array;  // An array of integers used to compute primes
		
		// Size of array is maxNumber + 1 instead of maxNumber
		// because we want to map a number x with array entry array[x]
		array = new int[maxNumber + 1];
		
		// Initialize array starting at 2
		for (int i=2; i<=maxNumber; i++) {
			array[i] = i;
		}
		
		// Compute the primes by removing multiple of primes (those set
		// to zero). The limit could have been maxNumber but is more efficient
		// to go to up to the sqrt(maxNumber).  
		for (int i=2; i<=(int)Math.sqrt(maxNumber); i++) {
			for (int j=2*i; j <= maxNumber; j+=i) {
				array[j] = 0;
			}
		}
		
		// Display the primes
		for (int i=2; i<=maxNumber; i++) {
			if (array[i] != 0) {
				System.out.println(array[i]);
			}
		}
		
	}
	
	/**
	 * A simple class tester
	 * @param args Unused
	 */
	static public void main(String[] args) {
		CommentsGood good = new CommentsGood();
		good.displayPrimes(20);  // Simple test case
	}
}