java中方法的使用 有无返回值及有无参数-0512

import java.util.Scanner;
class Demo03 
{
    public static void main(String[] args) 
    {
        //juxing();
        //shuzi();
         /*Scanner sc = new Scanner(System.in);
         System.out.println("输入行");
        int m = sc.nextInt();
         System.out.println("输入列");
        int n = sc.nextInt();
        juxing1(m,n);*/
        Scanner sc = new Scanner(System.in);
        System.out.println("输入");
        double a = sc.nextDouble();
        System.out.println("输入");
        double b = sc.nextDouble();
        System.out.println("输入");
        double c = sc.nextDouble();
        double avg = avg(a,b,c);
        System.out.print(avg);
    }
    public static void juxing(){
            for(int i = 0;i<3;i++){
               for(int j = 0;j<3;j++){
                   System.out.print("*");
               }
                 System.out.println();
            }
    }
    public static int shuzi(){
               Scanner sc = new Scanner(System.in);
               System.out.println("输入");
               int sz = sc.nextInt();
               return sz;
    }
    public static void juxing1(int m,int n){
             for(int i = 0;i<m;i++){
               for(int j = 0;j<n;j++){
                   System.out.print("*");
               }
                 System.out.println();
            }
    }
    public static double avg(double a,double b,double c){
                 double avg = (a + b + c)/3;
                 return avg;
    }
}