COMP 328 All Assignments COMP 328 All Assignments | Page 9

28. Class Cap has been defined as a base class, and class BaseballCap inherits from class Cap. Is
the following Java statement legal? Explain why or why not.
29. Write a few lines of code that would place 2 radio buttons labeled on and off side by side
into the top part of a JFrame based window. Assume that the code you are writing is inside the
constructor of an application which inherits from JFrame. Declare any variables that you need.
You should only need 6-8 lines of code.
30. This Java application is supposed to do the following. There are 2 text fields for user input.
The first is used to input a voltage value. The second is used to input a resistance value in ohms.
All values are floating point values. The user clicks a button to perform a calculation. One
button causes the program to calculate and display the current flowing through the resistor, /
R. Another button causes the program to calculate the power being dissipated by the resistor, *
V. The result of the selected calculation is displayed in a single output text area. The output
string should say something like this: “10 volts dropped across 1000 ohms creates 0.1 amps.”
Clicking of a button generates the event which causes the program to do the selected
calculation and update the output area. The user interface has already been setup in the class
that follows. Your job is to implement the ButtonHandler nested inner class which handles
button events, does the requested calculation and displays the appropriate result.