java - 计算循环中浮点数的总和？

Question

好的，所以我只是问了有关循环内方法的问题。好吧，我得到了大部分答案；但是，我的 sum() 方法仍然不起作用。例如，我将 5 放在数字 3 次，这三个数字的总和应该是 15。所以在整个循环中的某个地方，一个数字不会被添加到变量 add 中。任何帮助将不胜感激，谢谢。

// File:     RandyGilmanP2.java
// Author:   Randy L. Gilman
// Date:     10/5/2013
// Purpose:  Design and implement a Java program that will gather a group of 
//           floating point numbers and determine the sum and average of the 
//           data entered. The program should use separate methods for inputting 
//           the data, calculating the sum, calculating the average, and 
//           displaying the results. A sentinel value should be used to indicate 
//           the user has completed entering their numbers.  The output should 
//           display a message that includes the count of the numbers entered, 
//           the sum of the numbers and the average of the numbers. If the sum 
//           of the numbers is greater than 100, a warning message should be 
//           displayed indicating “values have exceeded a sum 100”.

import javax.swing.JOptionPane;

public class RandyGilmanP2 {//Begin class


    public static void main(String[] args) {//Begin main
        JOptionPane.showMessageDialog(null, "Hello Welcome to Sum and Average"
                + "\n   of a Number Calculator Program" 
                + "\n                 By: Randy Gilman");
        //Declare variables
        float add = 0;//used to store the sum of the numbers inputed
        float numb = input();//used to store the value of Input() method
        float average;
        int count = 0;// Used as a counter variable
        //Loop that will be controlled by a sentenil value
        while (numb != 0) {//Begin for loop
            count += 1;
            //Call Input method    
             numb = input();
            //Method to find the sum of all the numbers inputed
            add = sum(add,numb); 
            //Used to find the average of all the numbers entered (sum / count)
        }//End for loop
        average = avg(add,count);//used to store the average of the numbers
        results(count,add,average);
    }//End Main


   public static float input(){//Begin Method
         //Will keep gathering input from user until input is equal to 0
         String NumberString = JOptionPane.showInputDialog("Enter a floating point number"
            + " (The program ends when 0 is entered):");
             //Convert string to float
            float number = Float.parseFloat(NumberString);
            return number;


    }//End Method 

    public static float sum(float sum, float numb2){//Begin method
            //Add number to the previous number to compute total
            sum += numb2; 
            if (sum > 100)
                JOptionPane.showMessageDialog(null, "***WARNING***" + "\n"
                        + "            The sum of your numbers exceed 100");
            return sum;    
        }//End Method

        public static float avg(float num1, float num2){
            //Declare variables 
            float result;
            //Preform calculation of average
            result = num1 / num2;
            return result;

        }//End Method

        public static void results(int counter, float addition, float aver){//Begin method
            //Declare variables
            JOptionPane.showMessageDialog(null,"The total amount of numbers you entered are: " + counter);
            JOptionPane.showMessageDialog(null,"The sum of the numbers you have entered is: " + addition);
            JOptionPane.showMessageDialog(null,"The average of the numbers you have entered is: " + aver);
        }//End Method

}//End Class

Answer 1

在添加之前，您正在从输入中读取下一个数字。尝试：

    while (numb != 0) {//Begin for loop
        count += 1;
        //Method to find the sum of all the numbers inputed
        add = sum(add,numb);             
        //Call Input method    
        numb = input();
    }

Answer 2

import javax.swing.JOptionPane;
import javax.swing.UIManager;

public class RandyGilmanP2 {//Begin class

public static float result;
public static float quantity;

public static void main(String[] args) {
    try{
    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());

    JOptionPane.showMessageDialog(null, 
            "Hello Welcome to Sum and Average"
            + "\n   of a Number Calculator Program" 
            + "\n   By: Randy Gilman");

    for(float f = 0; (f = getInput()) != 0;){
        quantity++;
        result += f;
    }

            if(result > 100){
                JOptionPane.showMessageDialog(null, "WARNING, the sum of your numbers is greater than 100!");
            }

    JOptionPane.showMessageDialog(null, "Results:\nQuantity of numbers: " + quantity + "\nAverage of numbers: " + (result/quantity) + "\nSum of numbers: " + result);
    }catch(Exception e){
        JOptionPane.showMessageDialog(null, "Something went wrong:\n" + e.getMessage());
    }
}

public static float getInput() throws NumberFormatException{
    return Float.parseFloat(JOptionPane.showInputDialog("Enter a floating point number (The program ends when 0 is entered)"));
}

}//End Class

那堂课一团糟，我对此感到不安，请使用这个。