public class ArrayOfArraysDemo2 {
    public static void main(String[] args) {
        int[][] aMatrix = new int[4][];

	//populate matrix
        for (int i = 0; i < aMatrix.length; i++) {
	    aMatrix[i] = new int[5];	//create sub-array
	    for (int j = 0; j < aMatrix[i].length; j++) {
	        aMatrix[i][j] = i + j;
	    }
        }

        //print matrix
        for (int i = 0; i < aMatrix.length; i++) {
	    for (int j = 0; j < aMatrix[i].length; j++) {
	        System.out.print(aMatrix[i][j] + " ");
	    }
	    System.out.println();
        }
    }
}