COMP 274 All Assignments COMP 274 All Assignments | Page 4

For output, you should build a formatted string which includes tabs and new lines to represent
your table. JOptionPanes by themselves are not capable of properly formatting tabs. However,
there is another Java class which can be used with JOptionPanes to correctly display a
formatted string. The JTextArea class understands all string formatting instructions. The
following illustrates how to use the JTextArea class with a JOptionPane to display a formatted
string.
#import javax.swing.JOptionPane;
#import javax.swing.JTextArea;
String output = “This \t is \t a \t formatted \t string. \n”;
// Create a new JTextArea object
JTextArea area = new JTextArea( );
// Place a formatted string into the JTextArea
area.setText( output );
// Place the text area into the JOptionPane
JOptionPane.showMessageDialog( null, area, “Title for dialog box”,
JOptionPane.INFORMATION_MESSAGE );
For each of the two programming problems, create an Eclipse project and develop a Java
program to solve the problem. Make sure to capture a sample of your program’s output. The
best way to do this is to click on the console window you want to capture and then press the Alt
and PrintScreen keys at the same time. Then paste your captured screen image into a Word
document. For each of the two programs, put the screen capture followed by a copy of your
source code into your Word document.
Random Numbers in Java
There are two different classes available to generate random numbers in Java. The static
method random from the Math class can be used to generate a random floating point number
from 0 up to but not including 1. This number can be scaled to whatever range of random
numbers is desired.
(int)(Math.random( ) * 10); //results in an integer between 0 and 9