buildastring.java

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

import javax.swing.*;
public class BuildAString
{
  public static void main(String[] args)
  {
    double length, width, area;
    String output;
    length = 27.3;                           
    output = "The length of the rectangle is " + length;  
    width = 13.4;
    output += "\nThe width of the rectangle is " + width;
    area = length * width;
    output += "\nThe area of the rectangle is " + area;
    JOptionPane.showMessageDialog(null, output, "Program 3-5", 
                                  JOptionPane.INFORMATION_MESSAGE);
                                  
    System.exit(0); 
  }
}