macbook-pro:235lect05 smtuttle$ jshell
|  Welcome to JShell -- Version 16.0.1
|  For an introduction type: /help intro

jshell> import javax.swing.*;

jshell> JOptionPane simpleDialog = new JOptionPane();
simpleDialog ==> javax.swing.JOptionPane[,0,0,0x0,invalid,layout=j ... T_OPTION,wantsInput=false]

jshell> simpleDialog.showMessageDialog(null, "Welcome to\nCS 235");

jshell> String input = JOptionPane.showInputDialog("Please enter a color: ");
input ==> "red"

jshell> input = JOptionPane.showInputDialog("Please enter a color: ");
input ==> null

jshell> input = JOptionPane.showInputDialog("Please enter a color: ");
input ==> null

jshell> input = JOptionPane.showInputDialog("Please enter a color: ");
input ==> ""

jshell> 
macbook-pro:235lect05 smtuttle$