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Hour 15: Responding to User Input

Notes and Corrections

• The LottoMadness applet mentioned during this hour is on the Lottorobics page.

Source Files

• KeyView.class
• KeyView.java
• LottoEvent.class
• LottoEvent.java
• LottoEvent15.class
• LottoEvent15.java
• LottoEvent16.class
• LottoEvent16.java
• LottoMadness.class
• LottoMadness.java
• LottoMadness15.class
• LottoMadness15.java
• LottoMadness16.class
• LottoMadness16.java

Reader Questions

• Question: Why do you often import a class and also one of its sub-classes, as in the KeyView application when you import java.awt.* and java.awt.event.*. Couldn't the first of these statements include the second?
  Answer: Though the names of the java.awt and java.awt.event packages look like they are related, there's no such thing as inheritance for packages in Java. One package cannot be a subpackage of another.
  When you use an asterisk in an import statement, you are making all of the classes in a package available in a program.
  The asterisk only works on classes, not packages. The most a single import statement can load is the classes of a single package.

Activities

• Solution 1: LottoMadness15.java, LottoMadness15.class, LottoEvent15.java, and LottoEvent15.class.
• Solution 2: LottoMadness16.java, LottoMadness16.class, LottoEvent16.java, and LottoEvent16.class.