Java cares about type. It wont let you do something bizarre and dangerous like stuff a Giraffe reference into a Rabbit variable - what happens when someone tires to ask the so-called rabbit to hop()? And it won’t let you but a floating point number into an integer variable, unless you acknowledge to the compiler that you know you might lose precision (like, everything after the decimal point).

The compiler can spot most common problems:

Rabbit roger = new Giraffe();

When you see a statement like: " an object of type X ", think of type and class as synonyms.

How do we create a custom object?

• There is actually no such thing as an object variable.
• There's only an object reference variable.
• An object refference variable holds bits that represent a way to access an object.
• It doesn't hold the object itself, but it holds something like a pointer. Or an address. Except, in Java we don't really know what is inside a reference variable. We do know that whatever it is, it represents one and only one object. And the JVM knows how to use the reference to get the object.

Think of a Dog reference variable as a Dog remote control. You use it to get the object to do something. (invoke methods/behaviors )

Dog snoopy = new Dog();
snoopy.bark();

• Objective:
  • To create tests that ensure expected behavior of each class:
    • Cat
    • Dog
    • AnimalFactory
    • CatHouse
    • DogHouse
• Purpose:
  • To establish familiarity with Test-Driven-Development (TDD) practices.
• Getting context:
  • Click here to gain more familiarity with TDD-structured programming.

• Create tests for void setName(String name)
  • ensure that when .setName is invoked on an instance of Cat, the name field is being set to the respective value.
• Create tests for setBirthDate(Date birthDate)
  • ensure that when .setBirthDate is invoked on an instance of Cat, the birthDate field is being set to the respective value.
• Create tests for String speak()
  • ensure that when .speak is invoked on an instance of Cat, the value "meow!" is returned.
• Create tests for void eat(Food food)
  • ensure that when .eat is invoked on an instance of Cat, the numberOfMealsEaten is increased by 1.
• Create tests for Integer getId()
  • ensure that when .getId is invoked on an instance of Cat, the respective id value is returned.
• Create test to check Animal inheritance; google search java instanceof keyword
  • ensure that a Cat is an instanceof an Animal
• Create test to check Mammal inheritance; google search java instanceof keyword
  • ensure that a Cat is an instanceof a Mammal

• Create tests for void setName(String name)
  • ensure that when .setName is invoked on an instance of Dog, the name field is being set to the respective value.
• Create tests for setBirthDate(Date birthDate)
  • ensure that when .setBirthDate is invoked on an instance of Dog, the birthDate field is being set to the respective value.
• Create tests for String speak()
  • ensure that when .speak is invoked on an instance of Dog, the value "bark!" is returned.
• Create tests for void eat(Food food)
  • ensure that when .eat is invoked on an instance of Dog, the numberOfMealsEaten is increased by 1.
• Create tests for Integer getId()
  • ensure that when .getId is invoked on an instance of Dog, the respective id value is returned.
• Create test to check Animal inheritance; google search java instanceof keyword
  • ensure that a Dog is an instanceof an Animal
• Create test to check Mammal inheritance; google search java instanceof keyword
  • ensure that a Dog is an instanceof an Mammal

• Create Test for Animal createDog(String name, Date birthDate)
  • ensure that when .createDog is invoked on AnimalFactoryTest a Dog is created with the respective name and birthDate value.
• Create Test for Animal createCat(String name, Date birthDate)
  • ensure that when .createCat is invoked on AnimalFactoryTest a Dog is created with the respective name and birthDate value.

• Create tests for void add(Cat cat)
  • ensure that when .add is invoked on the CatHouse, a respective Cat object can be retrieved from the house.
• Create tests for void remove(Cat cat)
  • ensure that when .remove is invoked on the CatHouse, a respective Cat object can no longer be retrieved from the house.
• Create tests for void remove(Integer id)
  • ensure that when .remove is invoked on the CatHouse, a Cat object with the respective id can no longer be retrieved from the house.
• Create tests for Cat getCatById(Integer id)
  • ensure that when .getCatById is invoked on the CatHouse, a Cat with the respective id is returned.
• Create tests for Integer getNumberOfCats()
  • ensure that when .getNumberOfCats() is invoked on the CatHouse, the respective number of Cat objects is returned.

• Create tests for void add(Dog dog)
  • ensure that when .add is invoked on the DogHouse, a respective Dog object can be retrieved from the house.
• Create tests for void remove(Integer id)
  • ensure that when .remove is invoked on the DogHouse, a respective Dog object can no longer be retrieved from the house.
• Create tests for void remove(Dog dog)
  • ensure that when .remove is invoked on the DogHouse, a Dog object with the respective id can no longer be retrieved from the house.
• Create tests for Dog getDogById(Integer id)
  • ensure that when .getCatById is invoked on the DogHouse, a Dog with the respective id is returned.
• Create tests for Integer getNumberOfDogs()
  • ensure that when .getNumberOfDogs() is invoked on the DogHouse, the respective number of Dog objects is returned.