12A
Write the interface Growable. Growable interface has one method, grow. The grow method takes a double parameter percentToGrow as a parameter and does not return any value.
Now modify the class Circle included in Codecheck to implement the Growable interface. Circle's grow() method will increase the radius by the given percent.
For the draft, just write the Growable interface. There a hidden class Fake in Codecheck. It let's me test your interface. Do not worry about it. You can not compile and execute the Runner class in Bluej. This is another problem you will have to test in Codecheck. You will not write a Fake class.
You will need to resubmit your interface along with the Circle to Codecheck or the final
12B
Modify the class Country to implement the Comparable interface from the Java library. (Do not write your own interface). Countries are ordered by area. One Country is smaller than another if its area is smaller. If two countries have the same area, the one with the name that comes first in alphabetical order is smaller.
For the draft, add the implements Comparable clause to the Country class and then implement compareTo as a stub that always returns 0.
12C
Implement a subclass of Product called Book. Book has a String instance variable, author, in addition to description and price.
Provide the instance variable and methods
public void setAuthor(String newAuthor) public String getAuthor()public boolean sameAuthor( Book other)returns true if the books have the same author. Otherwise falseFor the draft, start the Book class as a subclass of Product. Provide the new instance variable, author. Write the constructor that takes price, description, and author, in that order. Be sure to initialize all the instance variables. Implement sameAuthor as a stub. Remember that if a stub's return type is boolean, return false.