printing out a 2-D array in Matrix format

Question

How can I print out a simple int [][] in the matrix box format like the format in which we handwrite matrices in. A simple run of loops doesn\'t apparently work. If it helps

Answer 1

To properly format numbers in columns, it's best to use printf. Depending on how big are the max or min numbers, you might want to adjust the pattern "%4d". For instance to allow any integer between Integer.MIN_VALUE and Integer.MAX_VALUE, use "%12d".

public void printMatrix(int[][] matrix) {
    for (int row = 0; row < matrix.length; row++) {
        for (int col = 0; col < matrix[row].length; col++) {
            System.out.printf("%4d", matrix[row][col]);
        }
        System.out.println();
    }
}

Example output:

 36 913 888 908
732 626  61 237
  5   8  50 265
192 232 129 307