Classes & Objects

Using and Creating Classes

new
dot operator
instance variables
methods

Deitel ch 3

Classwork

When example code is given, you may use it as a model when doing assignments, unless I say otherwise. You should use nothing beyond what we have covered in class or is given in example code (e.g. even if you know about accessors and mutators, don't use them yet).

Part A

Create a project and add to it the given example classes Hero and Monster (easiest way to do this is to add classes with those names, then copy-paste my code) You will probably need to fix the package statement to match your package name.

Call your class with a main method HeroAndMonster.

☑ In the main method:

create a Hero (remember to use "new").
give the Hero a name of your choosing (set the name instance variable)
set the Hero's hit points
make the Hero rest, then run

(You can base this code on HeroHarness but use different variable names and values. )

☑ Continuing in main:

create a Monster
give the Monster a name of your choosing
make the Monster attack
set your hero's enemy to be your Monster
print out your Monster's name without using your local Monster variable (must work even if we went back and changed the monster's name value) (hint: who else in the main knows about the monster, other than the local monster variable?)
let your Monster eat your Hero by passing your Hero variable into the parentheses of the Monster's eat method
print out the Hero's new name and number of hit points

Part B

You will create a class modeling some specific type of creature. You can choose any type of creature you want -- capybara, grue, naked mole rat, creeper, zombie dinosaur, whatever except the examples we've already done such as generic monster, cat, dog, or bunny. You can use Hero as a model. Name the class based on the specific type of creature it is modeling (i.e. public class ZomebieDino, not just public class Creature)

☑ Create the new class in the same package as part A. If it shows up in a different package (<default package>), you didn't do new on the package, drag it to the right package.

☑ For your new creature class

give it a String instance variable to hold its name
give it an int instance variable to keep track of how much of something it has (do not use hit points) e.g. how many balls of yarn a cat has collected, how many bales of hay a horse has eaten, how many cities godzilla has stomped.
add a method that, when called, increases (or decreases) this count by 1, and prints what has happened e.g. stompCity() could print "Monster-kun has stomped another city! That's 8 total! Tokyo is next!" (nothing beyond printing and changing the value of the variable required, you can copy the run method from the example code and just modify it.)
add an appropriate toString method
add a method for some other behavior appropriate for your creature. This method should just print a description of the action, using the name of the creature, but it may also change an instance variable if you wish (again, you can just copy from the example code and make changes)

☑ Further down in the main of your HeroAndMonster, create an instance of your new class, and test setting all variables and calling all methods.