AP Computer Science A Practice Quiz: Objects: Instances of Classes
Written by AP Content Team, Verified for 2026 AP Exams, Last updated: May 2026
Test your understanding with short quizzes. This quiz has 14 questions to check your progress.
Question 1 of 14
All Questions (14)
A) A specific instance with defined attributes.
B) The memory address of an object.
C) A blueprint for creating objects.
D) A variable that holds an object reference.
Correct Answer: C
The provided content states that 'A class is the formal implementation, or blueprint, of the attributes and behaviors of an object.'
A) A formal implementation of attributes and behaviors.
B) A specific instance of a class.
C) A collection of common attributes for related classes.
D) The memory address where a class is stored.
Correct Answer: B
The content defines an object as 'a specific instance of a class with defined attributes.'
A) A class is an instance of an object.
B) An object is a blueprint for a class.
C) A class and an object are two terms for the same concept.
D) An object is created from the template defined by a class.
Correct Answer: D
A class acts as a blueprint or template, and an object is a specific instance created based on that template, as described in the provided content.
A) It creates a new `Car` object.
B) It declares a variable named `myCar` that can hold a reference to a `Car` object.
C) It defines the `Car` class.
D) It assigns a memory address to the `Car` class.
Correct Answer: B
This code declares a variable of a reference type. The variable `myCar` is created to hold a reference (or memory address) to a `Car` object, but it does not create the object itself.
A) The object itself.
B) The blueprint of the class.
C) The memory address of an object.
D) The common attributes of a superclass.
Correct Answer: C
The content explicitly states that 'A variable of a reference type holds an object reference, which can be thought of as the memory address of that object.'
A) To be a specific instance of another class.
B) To extend the attributes and behaviors of another class.
C) To contain common attributes and behaviors for related classes.
D) To hold the memory address of a subclass.
Correct Answer: C
The definition provided states that a superclass is a 'single class' used for 'putting common attributes and behaviors of related classes.'
A) A class that contains common attributes for other classes.
B) A class that extends a superclass.
C) A blueprint for creating superclasses.
D) A specific instance of a superclass.
Correct Answer: B
The content defines subclasses as 'Classes that extend a superclass.'
A) `Book` is the object, and `The Great Gatsby` is the class.
B) `Book` is the class, and `The Great Gatsby` is the object.
C) Both `Book` and `The Great Gatsby` are classes.
D) Both `Book` and `The Great Gatsby` are objects.
Correct Answer: B
`Book` is the blueprint or formal implementation (the class), while the specific book `The Great Gatsby` is a specific instance of that blueprint (the object).
A) A formal implementation of an object's behaviors.
B) A value that can be thought of as the memory address of an object.
C) A special type of class that contains common attributes.
D) The process of creating a new instance of a class.
Correct Answer: B
The provided text explicitly states that an object reference 'can be thought of as the memory address of that object.'
A) Create specific instances of the `Animal` class.
B) Place common attributes, like `age` or `name`, into the `Animal` class to be shared by `Dog` and `Cat`.
C) Ensure that `Dog` and `Cat` objects have different memory addresses.
D) Define the `Dog` and `Cat` classes as blueprints for the `Animal` class.
Correct Answer: B
The purpose of a class hierarchy is to put 'common attributes and behaviors of related classes into a single class called a superclass.' This avoids code duplication.
A) A `String` object has been created and is stored in `message`.
B) The `String` class has been defined.
C) The variable `message` has been created but does not yet refer to a specific `String` object.
D) The variable `message` holds the memory address of the `String` class itself.
Correct Answer: C
Declaring a reference variable only creates a variable that can hold a reference to an object. It does not create the object itself. The variable `message` is initialized to a null reference.
A) Ensure every object has a unique memory address.
B) Organize related classes and reuse code for common attributes and behaviors.
C) Create specific instances from a blueprint.
D) Declare variables that can store object references.
Correct Answer: B
The text explains that a class hierarchy is developed by putting 'common attributes and behaviors' into a superclass, which is a key principle of code reuse and organization.
A) memory address and reference type.
B) superclass and subclasses.
C) attributes and behaviors.
D) specific instance and hierarchy.
Correct Answer: C
The definition given is that 'A class is the formal implementation, or blueprint, of the attributes and behaviors of an object.'
A) A class is to an object as a recipe is to a specific cake that was baked.
B) A class is to an object as a driver is to a car.
C) A class is to an object as a house is to a specific room in that house.
D) A class is to an object as an ingredient is to a recipe.
Correct Answer: A
A recipe (the class) is the set of instructions or blueprint, while the specific cake baked from it (the object) is the actual instance. This aligns with the definition of a class as a blueprint.