如何在Java中调用方法

Question

import java.util.Scanner;
public class Question1 
{
    public static void main(String[] args) 
    {    

      Primary test = new Primary();
      test.Main();

    }
}


class Primary       
{
  double x;
  double y;
  double z;
  double Small;
  double Avg;
  int dad;
  final int userNumbers = 3;
  Scanner in = new Scanner(System.in);


  public void Main()
  {
      System.out.println("Please enter 3 numbers");
       x = in.nextInt();
       y = in.nextInt();
       z = in.nextInt();
       Primary test = new Primary();
       test.Smallest();
       test.Average();
       System.out.println("The average of the numbers is:" + Avg);
       System.out.println("The smallest of the numbers is:" + Small);
  }


  public void Smallest()
  {
      if(z < y && z < x)
          Small = z;
      if (x < z && x < y)
          Small = x;
      if (y < z && y < x)
          Small = y;  
  }

  public void Average()
  {
      Avg = x + y + z / userNumbers;   
  }
}

I have no clue what to do since everything ive tried either gives me an error or I'm just not doing it right. I'm not even sure I'm doing what the professor is asking me to do, and he never responds to his emails. If anyone could help me it would be greatly appreciated (And if I'm not doing what my professor is asking please let me know).

Heres his instructions + The assignment on page 248

Around Page 248. Practice Exercise E5.1.You will create one class that has three methods: main(), smallest(), and average(). main() reads the test data values and prints the results. You may want to do this in a loop. smallest() and average() do not read data values or print the results. The main() method reads the data values and prints the results.

Write the following methods and provide a program to test them. a. double smallest(double x, double y, double z), returning the smallest of the arguments b. double average(double x, double y, double z), returning the average of the arguments

Answer 1

Here try this....`

let me know how that works

import java.util.ArrayList;
import java.util.Scanner;
package javaapplication17;

public class Question1 {
    public static void main(String[] args) 
    {    
     double avg, small;
      Scanner in = new Scanner(System.in);

      System.out.println("Please enter 3 numbers");
       double x = in.nextInt();
       double y = in.nextInt();
       double z = in.nextInt();

       //Method calls -----------------------------------

       avg = average(x, y, z);
       small = smallest(x, y, z);

       //Method calls -----------------------------------


       System.out.println("The average of the numbers is: " + avg);
       System.out.println("The smallest of the numbers is: " + small);
      }


      public static double smallest(double x, double y, double z)
      {
          double small = 0;
       if(z <= y && z <= x)
           small = z;
       if (x <= z && x <= y)
           small = x;
       if (y <= z && y <= x)
           small = y;  

        return small;
      }

      public static double average(double x, double y, double z)
      {
          return (x + y + z) / 3.0;   
      }   
}

Answer 2

You do need to learn java to do this. See https://en.wikiversity.org/wiki/Java_Tutorial/Hello_World ! and others like it for hints.

To answer the question given to you, you only need one class - you have two. In that class, you need three methods. Two of the methods return values - you have them returning a void. You shouldn't need any field variables in your class.

Structure the class as in the tutorial link. (This isnt' a working answer - you still have to do the homework.)

public class Question1 {

    public static void main( String[] args ) {

        double x, y, z;

        // Add your a loop here to collect your x, y and z
        // data and process it
        while (true) {
           // Collect the data ...

           // Call the methods
           double smallest = smallest(x, y, z);
           double average = average(x, y, z);

           // Do something with the results
        }
    }

    public static double smallest(double x, double y, double z) {

        double smallValue;

        // Add your logic and set smallValue

        return smallValue;

    }

    public static double average(double x, double y, double z) {

        // Calculate the average and return that value
        // as in the smallest method...

    }
}

To test the functions, write another program like the following:

import Question1;

public class TestQuestion1 {

    public static void main( String[] args ) {

        // Add test code here. Something like 
        double result = Question1.smallest(1.0, 2.0, 3.0)
        //  Check that the result is 1.0

        //  Add other tests - output the results

}