20201020_19 2차원배열

arr.length;

package pro;

public class Pro01 {

	public static void main(String[] args) {
		int[][] arr = new int[5][5];
		int sum = 0;
		int count = 1;

		for (int i = 0; i < arr.length; i++) {
			for (int j = 0; j < arr.length; j++) {
				arr[i][j] = count;
				count++;
				System.out.printf("%4d" ,arr[i][j]);
				if (arr[i][j]%5 ==0 ) {
					System.out.println(" ");
				}
			}

		}//for
		for (int i = 1; i < arr.length; i++) {
			for (int j = 0; j < i; j++) {
				sum += arr[i][j];
			}
			}
		System.out.println("합은:"+ sum);

	}

}