Question 26 :
How can the Checkbox class be used to create a radio button?
By associating Checkbox objects with a CheckboxGroup.
Question 27 :
Which non-Unicode letter characters may be used as the first character of an identifier?
The non-Unicode letter characters $ and _ may appear as the first character of an identifier
Question 28 :
What restrictions are placed on method overloading?
Two methods may not have the same name and argument list but different return types.
Question 29 :
What happens when you invoke a thread's interrupt method while it is sleeping or waiting?
When a task's interrupt() method is executed, the task enters the ready state. The next time the task enters the running state, an InterruptedException is thrown.
Question 30 :
What is the return type of a program's main() method?
A program's main() method has a void return type.