> javac -classpath .:/run_dir/junit-4.12.jar:target/dependency/* -d . Main.jcQ ×l ution.java Main.java:3: error: class Test is public, should be declared in a file named Test.j ava public class Test { 1 error compiler exit status 1

In previous chapters, you have created programs for the Greenville Idol competition. Now create a Contestant class with the following characteristics: The Contestant class contains public static arrays that hold talent codes and descriptions. Recall that the talent categories are Singing Dancing, Musical instrument, and Other. The class contains an auto-implemented property that holds a contestants name. The class contains fields for a talent code and description. The set accessor for the code assigns a code only if it is valid. Otherwise, it assigns I for Invalid. The talent description is a read-only property that is assigned a value when the code is set. Modify the GreenvilleRevenue program so that it uses the Contestant class and performs the following tasks: The program prompts the user for the number of contestants in this years competition; the number must be between 0 and 30. The program continues to prompt the user until a valid value is entered. The expected revenue is calculated and displayed. The revenue is $25 per contestant. The program prompts the user for names and talent codes for each contestant entered. Along with the prompt for a talent code, display a list of the valid categories. After data entry is complete, the program displays the valid talent categories and then continuously prompts the user for talent codes and displays the names of all contestants in the category. Appropriate messages are displayed if the entered code is not a character or a valid code.

a. Write a FractionDemo program that instantiates several Fraction objects and demonstrates that their methods work correctly. Create a Fraction class with fields that hold a whole number, a numerator, and a denominator. In addition: Create properties for each field. The set access or for the denominator should not allow a 0 value; the value defaults to 1. Add three constructors. One takes three parameters for a whole number, numerator, and denominator. Another accepts two parameters for the numerator and denominator; when this constructor is used, the whole number value is 0. The last constructor is parameterless; it sets the whole number and numerator to 0 and the denominator to 1. (After construction, Fractions do not have to be reduced to proper form. For example, even though 3/9 could be reduced to 1/3, your constructors do not have to perform this task.) Add a Reduce() method that reduces a Fraction if it is in improper form. For example, 2/4 should be reduced to 1/2. Add an operator+() method that adds two Fractions. To add two fractions, first eliminate any whole number part of the value. For example, 2 1/4 becomes 9/4 and 1 3/5 becomes 8/5. Find a common denominator and convert the fractions to it. For example, when adding 9/4 and 8/5, you can convert them to 45/20 and 32/20. Then you can add the numerators, giving 77/20. Finally, call the Reduce() method to reduce the result, restoring any whole number value so the fractional part of the number is less than 1. For example, 77/20 becomes 3 17/20. Include a function that returns a string that contains a Fraction in the usual display format—the whole number, a space, the numerator, a slash (D, and a denominator. When the whole number is 0, just the Fraction part of the value should be displayed (for example, 1/2 instead of 0 1/2). If the numerator is 0, just the whole number should be displayed (for example, 2 instead of 2 0/3). b. Add an operator*() method to the Fraction class created in Exercise 11a so that it correctly multiplies two Fractions. The result should be in proper, reduced format. Demonstrate that the method works correctly in a program named FractionDemo2. c. Write a program named FractionDem03 that includes an array of four Fractions. Prompt the user for values for each. Display every possible combination of addition results and every possible combination of multiplication results for each Fraction pair (that is, each type will have 16 results).