APCSA Unit 2 Quiz

In Java, what is a class defined as?

• A) A collection of objects

• B) A type of data structure

• C) A programmer-defined blueprint from which objects are created

• D) A function that performs operations

What is an object in Java?

• A) A reference to a class

• B) A method within a class

• C) An instance of a class

• D) A variable type

What is an instance variable?

• A) A type of method that performs an action in a class.

• B) A variable defined in a class that represents an attribute of an object.

• C) A piece of data passed into a method when it is called.

• D) A variable that is shared among all instances of a class.

What does the 'int' in the declaration 'private int xLocation;' represent?

• A) A sequence of characters, like "purple"

• B) Decimal numbers, like 2.5 or 92.81

• C) Whole numbers, like 7 or 6784

• D) True or false values

What is the visibility of the instance variable 'xLocation' as declared in 'private int xLocation;'?

• A) Public

• B) Protected

• C) Default

• D) Private

What happens to instance variables when an object is instantiated?

• A) They are shared with other instances of the same class.

• B) They are deleted and must be redefined.

• C) Each object gets its own copy of the instance variables.

• D) They become static and unchangeable.

What is inheritance in object-oriented programming?

• A) A method by which one class receives properties from another class.

• B) A principle where a subclass inherits the attributes and behaviors of a superclass.

• C) The process by which a function calls itself.

• D) A technique for encapsulating data within a class.

Which of the following best describes a subclass in the context of inheritance?

• A) A class that inherits methods and properties from another class.

• B) A class that provides methods and properties to other classes.

• C) A class that cannot be instantiated.

• D) A class that does not share any relationship with other classes.

What is the purpose of attributes in a class?

• A) To define the state of an object

• B) To perform operations

• C) To define the class name

• D) To define the superclass

What is a no-argument constructor in Java?

• A) A constructor that takes no parameters.

• B) A constructor that takes any number of parameters.

• C) A constructor that takes exactly one parameter.

• D) A constructor that cannot be called.