Example Java Code for a Matrix which is a two-dimensional array.

Matrix.java

/**
 * This class demonstrates how to write code that can process a matrix (i.e. a two-dimensional array)
 * Note that the method printMatrix will print any two-dimensional array of ints
 * 
 * @author kaydell
 * 
 * Copyright, 2013, Kaydell Leavitt, All Rights Reserved
 * 
 * {link http://simple.wikipedia.org/wiki/Matrix_%28mathematics%29}
 *
 */
public class Matrix {

  /**
	 * This method will print any two-dimensional array of ints.
	 * Note that in Java, a two-dimensional array is implemented
	 * by an array of arrays.
	 * 
	 * @param anyIntMatrix
	 */
	public static void printMatrix(int[][] anyIntMatrix) {
		for (int row = 0; row < anyIntMatrix.length; row++) {
			for (int column = 0; column < anyIntMatrix[0].length; column++) {
				System.out.print(anyIntMatrix[row][column]);
			}
			System.out.println();
		}
	}
	
	/**
	 * This method tests the method called "printMatrix()"
	 * 
	 * @param args Not used.
	 */
	public static void main(String[] args) {
		int[][] aPaticularIntMatrix = { {1, 2, 3}, { 4, 5, 6} };
		printMatrix(aPaticularIntMatrix);
	}

}