Sams Teach Yourself Java 2 in 21 Days, Second Edition

Exercises

To extend your knowledge of the subjects covered today, try the following exercises:

• Create an application that uses FocusListener to make sure that a text field's value is multiplied by -1 and redisplayed any time a user changes it to a negative value.

• Create a simple calculator that adds the contents of two text fields whenever a button is clicked and displays the result as a label.

Where applicable, exercise solutions are offered on the book's Web site at http://www.java21days.com.