Dialog Box and Static Methods

Displaying Text in a Dialog Box

The programs presented thus far display output in the command window. Many applications

use windows or dialog boxes (also called dialogs) to display output. Web browsers

such as Firefox, Internet Explorer, Chrome and Safari display web pages in their own windows.

E-mail programs allow you to type and read messages in a window. Typically, dialog

boxes are windows in which programs display important messages to users. Class JOption-Pane provides prebuilt dialog boxes that enable programs to display windows containing

messages—such windows are called message dialogs.

Introducing static Methods

JOptionPane method showMessageDialog is a so-called static method. Such methods

often define frequently used tasks. For example, many programs display dialog boxes, and

the code to do this is the same each time. Rather than requiring you to “reinvent the

 

wheel” and create code to display a dialog, the designers of class JOptionPane declared a

static method that performs this task for you. A static method is called by using its class

name followed by a dot (.) and the method name, as in
ClassName.methodName( arguments )