Core Java Quiz

What is object-oriented programming?

• Object-oriented programming is a programming paradigm that organizes data and behavior into reusable structures called objects.

• Object-oriented programming is a programming paradigm that does not support code reusability.

• Object-oriented programming is a programming paradigm that uses only functions and procedures.

• Object-oriented programming is a programming paradigm that focuses on procedural programming.

What are the four main principles of object-oriented programming?

• encapsulation, inheritance, polymorphism, and encapsulation

• encapsulation, inheritance, polymorphism, and encapsulation

• encapsulation, inheritance, polymorphism, and encapsulation

• encapsulation, inheritance, polymorphism, and abstraction

What is a class in Java?

• A class in Java is a data type used to store multiple values.

• A class in Java is a built-in function that performs a specific task.

• A class in Java is a keyword used to define a method.

• A class in Java is a blueprint or template for creating objects.

What is an object in Java?

• An object in Java is a data type.

• An object in Java is an instance of a class.

• An object in Java is a method.

• An object in Java is a variable.

What is the difference between a class and an object?

• A class is a blueprint or template for creating objects, while an object is an instance of a class.

• A class is used to define functions, while an object is used to store data.

• A class is a specific type of object.

• A class and an object are the same thing.

What is inheritance in Java?

• Inheritance in Java is a mechanism where one class inherits the properties and behaviors of another class.

• Inheritance in Java is a feature that allows a class to have multiple superclasses.

• Inheritance in Java is a process of creating multiple instances of a class.

• Inheritance in Java is a way to create new classes from existing classes.

What is polymorphism in Java?

• Polymorphism in Java is a technique that allows a method to be overridden in different ways by different classes.

• Polymorphism in Java allows objects of different classes to be treated as objects of a common superclass.

• Polymorphism in Java refers to the ability of an object to take on many forms.

• Polymorphism in Java is a feature that allows one interface to be implemented by multiple classes.

What is encapsulation in Java?

• Encapsulation is the process of hiding the internal details of an object and providing a public interface to interact with it.

• Encapsulation is the process of converting an object into a different data type.

• Encapsulation is the process of combining multiple objects into a single object.

• Encapsulation is the process of exposing the internal details of an object and hiding the public interface.

What is abstraction in Java?

• Abstraction in Java is the concept of hiding internal implementation details and exposing only necessary information or methods to the outside world.

• Abstraction in Java is the process of converting a class into an interface.

• Abstraction in Java is the process of hiding the main method in a class.

• Abstraction in Java is the process of making a class abstract by using the abstract keyword.

What is the difference between abstract classes and interfaces in Java?

• An abstract class can implement multiple interfaces, while an interface can only extend one abstract class.

• An abstract class can be instantiated, while an interface cannot be instantiated.

• An abstract class cannot have any methods, while an interface can have both abstract and non-abstract methods.

• An abstract class can have both abstract and non-abstract methods, while an interface can only have abstract methods.