Object-Oriented Programming Quiz

What is the main benefit of encapsulation in object-oriented programming?

• It protects the internal state of an object

• It improves system performance

• It makes classes dependent on each other

• It allows global variables

How is encapsulation implemented in Java?

• By using private variables and public methods

• By using global variables

• By accessing private variables directly

• By avoiding the use of classes

What does encapsulation achieve?

• Restricting direct access to object data

• Increasing the complexity of code

• Making data public for easy access

• Removing the need for constructors

Which of the following best demonstrates encapsulation?

• Using getter and setter methods

• Accessing class variables directly

• Implementing multiple constructors

• Inheriting from a parent class

Why is encapsulation useful?

• It allows the implementation of data hiding

• It reduces the number of classes

• It makes debugging easier by exposing all variables

• It eliminates the need for interfaces

What is inheritance in object-oriented programming?

• A mechanism to create new classes from existing classes

• A way to pass data between classes

• A process of copying data from one class to another

• A method to create abstract classes

What keyword is used to implement inheritance in Java?

• extends

• implements

• inherits

• includes

Which of the following is true about inheritance?

• A subclass can inherit methods and variables from a superclass

• A subclass cannot override methods of a superclass

• Inheritance only applies to primitive data types

• Inheritance can only be used with interfaces

What is the primary benefit of inheritance?

• Code reuse

• Slower program execution

• The ability to declare all variables globally

• Simplifying program structure by avoiding classes

How does inheritance contribute to polymorphism?

• A subclass can be treated as an instance of its superclass

• It prevents method overriding

• It restricts the use of abstract classes

• It forces all methods to be final