求矩阵中各列数字的和 Exercise08

求矩阵中各列数字的和 Exercise08_01

 1 import java.util.Scanner;
 2 /**
 3  * @author 冰樱梦
 4  * 时间：2018年12月
 5  * 题目：求矩阵中各列数字的和
 6  *
 7  */
 8 public class Exercise08_01 {
 9     public static void main(String[] args){
10         Scanner input=new Scanner(System.in);
11         double m[][]=new double[3][4];
12         System.out.println("Enter a 3-by-4 matrix row:");
13         for(int i=0;i<m.length;i++){
14             for(int j=0;j<m[i].length;j++){
15                 m[i][j]=input.nextDouble();
16             }
17         }
18         
19         
20 //        System.out.println("Enter the columnIndex");
21 //        int columnIndex=input.nextInt();
22         
23         int columnIndex=0;
24         System.out.println("Sum of the elements at column "+columnIndex+" is "+sumColumn(m,columnIndex));
25         columnIndex=1;
26         System.out.println("Sum of the elements at column "+columnIndex+" is "+sumColumn(m,columnIndex));
27         columnIndex=2;
28         System.out.println("Sum of the elements at column "+columnIndex+" is "+sumColumn(m,columnIndex));
29         columnIndex=3;
30         System.out.println("Sum of the elements at column "+columnIndex+" is "+sumColumn(m,columnIndex));
31     }
32     public static double sumColumn(double m[][],int columnIndex){
33         double total=0;
34         for(int i=0;i<m.length;i++){
35             total+=m[i][columnIndex];
36         }
37         return total;
38     }
39 }