Interface + java-visual

What is the color of the water bottle in the image?

• Red

• Blue

• Green

• Yellow

Answer explanation

The answer can be found in the image, where the code for the water bottle interface defines the color as "Blue". The code is also visible in the image.

What is the name of the remote resource defined in the image?

• PetStore

• Pet

• CreatePet

• IdNotFound

Answer explanation

The answer can be found in the image, where the code defines a remote resource called "PetStore". The code is also visible in the image.

What is the output of the program?

• 2000

• Have a good day

• Static method

• None of the above

Answer explanation

The answer can be found in the image, where the code defines a variable called BONUS that is initialized to 2000. The code is also visible in the image.

What is the purpose of the CallBackInterface interface?

• To allow the WorkerClass to notify the MainActivity when it has finished its task.

• To allow the MainActivity to control the WorkerClass's behavior.

• To allow the WorkerClass to access the MainActivity's data.

• To allow the MainActivity to access the WorkerClass's methods.

Answer explanation

The answer is 1 because the CallBackInterface interface defines a single method, callback(), which is called by the WorkerClass when it has finished its task. The MainActivity implements the CallBackInterface interface, so it can receive the notification from the WorkerClass.

What is the output of the displayInfo() method?

• Person Name: JOHN, Person Age: 32

• Person Name: JOHN, Person Age: 21

• Person Name: InterfaceExamples, Person Age: 32

• Person Name: InterfaceExamples, Person Age: 21

Answer explanation

The answer is 1 because the displayInfo() method prints the PersonName and PersonAge variables, which are both initialized to JOHN and 32 in the InterfaceExamples class.

What is the HTTP method used to add a new pet to the store?

• GET

• POST

• PUT

• DELETE

Answer explanation

The answer is 2 because the postPet() method is annotated with the @RestMethod(method = "POST") annotation. This annotation indicates that the postPet() method uses the POST HTTP method.

Which of the following classes inherits from the Movable interface?

• MovablePoint

• MovableCircle

• Both MovablePoint and MovableCircle

• Neither MovablePoint nor MovableCircle

Answer explanation

The answer is 3 because both the MovablePoint and MovableCircle classes inherit from the Movable interface. The Movable interface defines the moveUp(), moveDown(), moveLeft(), and moveRight() methods, which are implemented by both the MovablePoint and MovableCircle classes.

What is the purpose of the ITable interface?

• To define the methods that must be implemented by any class that wants to be a table.

• To provide a way to access the data in a table.

• To allow different types of tables to be used in the same program.

• All of the above.

Answer explanation

The answer is 4 because the ITable interface defines the methods that must be implemented by any class that wants to be a table. This allows different types of tables to be used in the same program, and it also provides a way to access the data in a table.

Which of the following methods is declared as a private static method in the MyInterfaceInJava9 interface?

• printLines()

• method1()

• method2()

• mymethods()

Answer explanation

The answer is 1 because the printLines() method is declared as a private static method in the MyInterfaceInJava9 interface. This means that the printLines() method can only be called from within the MyInterfaceInJava9 interface, and it cannot be called from any other class.

Which of the following classes inherits from the Animal class?

• Cat

• Dog

• Bird

• All of the above

Answer explanation

The answer is 4 because all of the classes in the image inherit from the Animal class. The Animal class is a base class that defines the common properties and behaviors of all animals. The Cat, Dog, and Bird classes all inherit from the Animal class and add their own unique properties and behaviors.