Object Oriented Programming BlueJ Quiz

What is a class in object oriented programming?

• A blueprint for creating objects and providing initial values for state and implementations of behavior.

• A data structure in programming

• A type of function in programming

• A file that contains code in programming

Answer explanation

A class is a blueprint for creating objects and defining their initial values and behavior.

Explain the concept of an object in object oriented programming.

• An object is a real-world entity that has state and behavior.

• An object is a programming language used to create websites

• An object is a type of data structure used in programming

• An object is a mathematical equation used to perform calculations

Answer explanation

An object in object-oriented programming is a real-world entity with state and behavior.

How are classes and objects related in object oriented programming?

• Classes and objects are interchangeable in object oriented programming

• Classes are blueprints for objects, and objects are instances of classes.

• Objects are blueprints for classes, and classes are instances of objects

• Classes are unrelated to objects in object oriented programming

Answer explanation

Classes are blueprints for objects, and objects are instances of classes.

What is inheritance in object oriented programming?

• Inheritance is a feature that allows a class to inherit properties only from abstract classes

• Inheritance is a feature that allows a class to inherit properties from a subclass

• Inheritance is a feature that allows a class to inherit properties from multiple classes

• Inheritance allows a new class to inherit properties and behaviors from an existing class.

Answer explanation

Inheritance in object-oriented programming allows a new class to inherit properties and behaviors from an existing class.

Explain the concept of parent and child classes in inheritance.

• Parent and child classes have no relationship in inheritance.

• The child class is the class being inherited from, and the parent class is the class that inherits from the child class.

• The parent class is the class being inherited from, and the child class is the class that inherits from the parent class.

• The parent class is the class that inherits from the child class.

Answer explanation

The parent class is the class being inherited from, and the child class is the class that inherits from the parent class.

How does inheritance promote code reusability in object oriented programming?

• By allowing a new class to inherit properties and behaviors from an existing class.

• By removing the ability to reuse code

• By creating completely new classes from scratch

• By restricting the access to class properties and behaviors

Answer explanation

Inheritance promotes code reusability by allowing a new class to inherit properties and behaviors from an existing class.

What is polymorphism in object oriented programming?

• Inability of a function to behave differently based on the object it is acting upon

• Ability of a function to behave the same regardless of the object it is acting upon

• Ability of a function to behave differently based on the object it is acting upon

• A function's behavior is determined by the class it belongs to, not the object it is acting upon

Answer explanation

Polymorphism in object-oriented programming refers to the ability of a function to behave differently based on the object it is acting upon. This allows for flexible and dynamic behavior in the code.

Explain the concept of method overriding in polymorphism.

• Method overriding is when a subclass inherits all the methods from its parent class without any changes.

• Method overriding is when a subclass removes a method that is already provided by its parent class.

• Method overriding is when a subclass provides a specific implementation of a method that is already provided by its parent class.

• Method overriding is when a subclass provides a completely new method that is not related to its parent class.

Answer explanation

Method overriding is when a subclass provides a specific implementation of a method that is already provided by its parent class.

How does polymorphism contribute to the flexibility of object oriented programming?

• Polymorphism has no impact on the flexibility of object oriented programming

• Polymorphism allows different classes to be treated as instances of the same class.

• Polymorphism restricts the use of different classes in object oriented programming

• Polymorphism allows classes to only have one method

Answer explanation

Polymorphism allows different classes to be treated as instances of the same class, enhancing flexibility in object-oriented programming.

What is encapsulation in object oriented programming?

• Bundling data and methods into a single unit

• Separating data and methods into different units

• Combining data and methods with inheritance

• Encapsulation is not used in object oriented programming

Answer explanation

Encapsulation in object-oriented programming refers to bundling data and methods into a single unit, which is the correct choice.