More loop practice

Practice.java

public class Practice
{
	public static void main(String[] args) {

		// How can you replace the hard coded numbers
		// with a variable and print out the same thing 
		// as the code below?
		//
		// There's more than one way to do this.
		System.out.println(1);
		System.out.println(3);
		System.out.println(5);
		System.out.println(7);
		System.out.println(9);
		System.out.println(11);
		System.out.println(13);
		System.out.println(15);

		
		// How can you use a while loop to print out all multiples of 6
		// that are greater than 0 and less than a hundred?
		while (...) {
			...
		}

		// How can you use a for loop to do the same thing?
		for (...; ...; ...) {
			...
		}
		
		// Here I'm making an 12 x 12 2D array of zeros.
		int[][] arr = new int[12][12];

		// How can you set half of the 2D array to ones?
		// So it looks something like this (simplified):
		// 1 0
		// 1 0

		// Run the program and check your result:
		print2DArray(arr);

		// How can you set the top right quarter of the 2D array to ones?
		// So including the changes from the previous question, it should 
		// look something like this (simplified):
		// 1 1
		// 1 0

		// Run the program and check your result:
		print2DArray(arr);

		// Okay I'm a new 12 x 12 array of zeros.
		int[][] arr2 = new int[12][12];

		// How can you create a checkerboard pattern?
		// A simplified example:
		// 1 0 1 0
		// 0 1 0 1
		// 1 0 1 0

		// Run the program and check your result:
		print2DArray(arr2);
	}

	/* Pretty-prints a 2D array of integers to the screen. */
	public static void print2DArray(int[][] arr) {
		System.out.println("\n\nPrinting 2D array...");
		for (int i = 0; i < arr.length; i++) {
			for (int j = 0; j < arr[i].length; j++) {
				System.out.print(arr[i][j] + "\t");
			}
			System.out.println();
		}
	}
}