Java Proficiency Test¶

This two-part coding challenge will help you review your understanding of basic Java concepts including classes, objects, methods, variables, and logic.

Part 1: Pet Simulator (OOP Practice)¶

Goal: Practice using classes, constructors, methods, and objects.

Create a Java program with two classes: Dog and Cat.

Each class should have: - At least one instance variable (for example: name, age, or isHungry). - A constructor that initializes the instance variable(s). - A method:

Dog: Implement a method called bark() that prints a message like:
Rex says: Woof!
Cat: Implement a method called meow() that prints a message like:
Mittens says: Meow!

In a separate Main class (with a main method): - Create one Dog object and one Cat object. - Call each of their methods.

What this tests: - Creating classes and methods - Constructors and instance variables - Creating and using objects - Calling methods

Part 2: Pet Feeding System (Logic and Control Flow)¶

Goal: Practice using variables, if-statements, and logic.

Expand your existing Dog and Cat classes to include:

A boolean instance variable: isHungry.
A method called feed():
- If the pet is hungry, print a message like:
```
Feeding Rex...
```
  Then update isHungry to false.
- If the pet is not hungry, print a message like:
```
Rex is not hungry.
```

In your Main method: - Create a pet that is hungry. - Call feed() on it twice, and observe the output.

What this tests: - Use of boolean variables - If-statements and conditionals - Updating and checking object state

Optional Bonus Challenge¶

If you’re feeling confident, try the following:

Create a shared interface or abstract class called Pet with a method speak().
Implement and override speak() in both Dog and Cat.

This will give you practice with inheritance and polymorphism.

Completed¶

Justin Hollister
Mihai Popescu