averagenumbers.java

《A first book of java》by Gary J.Bronson 北大出版社

import javax.swing.*;
public class AverageNumbers
{
  public static void main(String[] args)
  {
    String s1, info, outMessage;
    
    final int MAXNUMS = 4;
    int count;
    double num, total, average;
    info = "This program will ask you to enter "
         + MAXNUMS + " numbers.";
    JOptionPane.showMessageDialog(null, info, "Program 5.7", 
                       JOptionPane.INFORMATION_MESSAGE);
    outMessage = "The average of the numbers:\n";
    count = 1;
    total = 0;
    while (count <= MAXNUMS)
    {
      s1 = JOptionPane.showInputDialog("Enter number " + count + ":");
      num = Double.parseDouble(s1);
      total = total + num;
      outMessage = outMessage + num + "  ";
      count++;
    }
    average = total / MAXNUMS;
    JOptionPane.showMessageDialog(null, outMessage + "\nis  " + average, 
                                  "Program 5-7", 
                                  JOptionPane.INFORMATION_MESSAGE);
    System.exit(0);  
  }
}