/**
 * MatrixAdd.java - 
 *   Method and test cases for matrix addition.  The method
 *   addMatrices computes the sum of two matrices.
 *
 *   For example:
 *       +-   -+   +-   -+   +-   -+
 *       |1 2 3|   |2 3 4|   |3 5 7|
 *       |4 5 6| + |5 4 3| = |9 9 9|
 *       |2 1 0|   |0 1 2|   |2 2 2|
 *       +-   -+   +-   -+   +-   -+    
 *
 * This program also contains a method for displaying an array. 
 */
class matrixAddition {

  public static void main (String[] args) {
  
    int[][] t1 = {{1, 2, 3}, {2, 3, 4}};
    int[][] t2 = {{3, 4, 5}, {6, 7, 8}};

    int[][] result;

    result = addMatrices(t1,t2);
    printMatrix(result);
  }

  /**
   * Add two rectangular matrices of integers and 
   * return a matrix with their sum. 
   */
  static int[][] addMatrices(int[][] m1, int[][] m2) {

    int[][] result = new int[m1.length][m1[0].length];
       
    for (int row=0; row<m1.length; row++) {  
      for (int col=0; col < m1[row].length; col++) {
        result[row][col] = m1[row][col] + m2[row][col];
      }
    }

    return result;
  }

  /**
   * Print the contents of a 2 dimensional array of integers.
   */
  static void printMatrix(int[][] printMe) {
    ...
  }
}