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;
    }
}