N阶矩阵及其对角线之和

由键盘输入N，求N阶矩阵，并计算出它正对角线的和。

import java.util.Scanner;public class Matrix {public void matrix(){int sum = 0;int n = 0;int array[][];System.out.print("请输入矩阵的阶数：");Scanner sc = new Scanner(System.in);n = sc.nextInt();System.out.print(n + "*" + n +" 阶矩阵如下所示");System.out.println();array = new int[n][n];for(int i=0;i<n;i++){for(int j=0;j<n;j++){array[i][j] = (int)(Math.random()*10);System.out.print(array[i][j]+"\t");if((j+1)%n == 0)System.out.println();if(i==j) sum=sum + array[i][j];}}System.out.print("矩阵主对角线元素之和为 :");System.out.print(sum); }public static void main(String[] args) {// TODO 自动生成的方法存根Matrix m = new Matrix();m.matrix();}}