Quiz Questions
For Chapter 9

THIS PAGE CONTAINS A SAMPLE quiz on material from Chapter 9 of this on-line Java textbook. You should be able to answer these questions after studying that chapter. Sample answers to all the quiz questions can be found here.

Question 1: What does it mean to say that a program is robust?

Question 2: Why do programming languages require that variables be declared before they are used? What does this have to do with correctness and robustness?

Question 3: What is "Double.NaN"?

Question 4: What is a precondition? Give an example.

Question 5: Explain how preconditions can be used as an aid in writing correct programs.

Question 6: Java has a predefined class called Throwable. What does this class represent? Why does it exist?

Question 7: Write a subroutine that prints out a 3N+1 sequence starting from a given integer, N. The starting value should be a parameter to the subroutine. If the parameter is less than or equal to zero, throw an IllegalArgumentException. If the number in the sequence becomes too large to be represented as a value of type int, throw an ArithmeticException.

Question 8: Some classes of exceptions require mandatory exception handling. Explain what this means.

Question 9: Consider a subroutine processData that has the header 

        static void processData() throws IOException

Write a try...catch statement that calls this subroutine and prints an error message if an IOException occurs.

Question 10: Why should a subroutine throw an exception when it encounters an error? Why not just terminate the program?

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