【正确答案】程序代码如下： public class GetArraySum //求5X5数组中对角线元素的和 { public static void main(String args[]) { double a[][]={ {9.0,8.0,7.0,6.0,5.0}, {11.0,12.0,13.0,14.0,15.0}, {20.0,19.0,18.0,17.0,16.0}, {31.0,32.0,33.0,34.0,35.0}, {51.0,52.0,53.0,54.0,55.0} }; double sum=0.0; for(int i=0;i<5;i++) for(int j=0;j<5;j++) if(i==j) sum=sum+a[i][j]; System.out.println("对角线元素的和："+sum); } }