求矩阵中各列数字的和 Exercise08_01

 import java.util.Scanner;
 /**
  * @author 冰樱梦
  * 时间：2018年12月
  * 题目：求矩阵中各列数字的和
  *
  */
 public class Exercise08_01 {
     public static void main(String[] args){
         Scanner input=new Scanner(System.in);
         double m[][]=new double[3][4];
         System.out.println("Enter a 3-by-4 matrix row:");
         for(int i=0;i<m.length;i++){
             for(int j=0;j<m[i].length;j++){
                 m[i][j]=input.nextDouble();
             }
         }

 //        System.out.println("Enter the columnIndex");
 //        int columnIndex=input.nextInt();

         int columnIndex=0;
         System.out.println("Sum of the elements at column "+columnIndex+" is "+sumColumn(m,columnIndex));
         columnIndex=1;
         System.out.println("Sum of the elements at column "+columnIndex+" is "+sumColumn(m,columnIndex));
         columnIndex=2;
         System.out.println("Sum of the elements at column "+columnIndex+" is "+sumColumn(m,columnIndex));
         columnIndex=3;
         System.out.println("Sum of the elements at column "+columnIndex+" is "+sumColumn(m,columnIndex));
     }
     public static double sumColumn(double m[][],int columnIndex){
         double total=0;
         for(int i=0;i<m.length;i++){
             total+=m[i][columnIndex];
         }
         return total;
     }
 }