Quick Answer: How Will A Class Protect The Code Inside It?

Which of these keywords can be used for a class which has been declared final?

A abstract class is incomplete by itself and relies upon its subclasses to provide complete implementation.

If we declare a class final then no class can inherit that class, an abstract class needs its subclasses hence both final and abstract cannot be used for a same class..

What happens if we put a key object in a HashMap which exists?

What happens if we put a key object in a HashMap which exists? Explanation: HashMap always contains unique keys. If same key is inserted again, the new object replaces the previous object. 5.

What is basic encapsulation?

Encapsulation is one of the fundamental concepts in object-oriented programming (OOP). It describes the idea of bundling data and methods that work on that data within one unit, e.g., a class in Java. This concept is also often used to hide the internal representation, or state, of an object from the outside.

What is encapsulation example?

Encapsulation in Java is a process of wrapping code and data together into a single unit, for example, a capsule which is mixed of several medicines. We can create a fully encapsulated class in Java by making all the data members of the class private. … The Java Bean class is the example of a fully encapsulated class.

What is the purpose of encapsulation?

Encapsulation is one of the fundamentals of OOP (object-oriented programming). It refers to the bundling of data with the methods that operate on that data. Encapsulation is used to hide the values or state of a structured data object inside a class, preventing unauthorized parties’ direct access to them.

How do you implement encapsulation?

How to implement encapsulation in java: 1) Make the instance variables private so that they cannot be accessed directly from outside the class. You can only set and get values of these variables through the methods of the class. 2) Have getter and setter methods in the class to set and get the values of the fields.

Why do we need abstraction?

The main purpose of abstraction is hiding the unnecessary details from the users. Abstraction is selecting data from a larger pool to show only relevant details of the object to the user. It helps in reducing programming complexity and efforts. It is one of the most important concepts of OOPs.

What is the functionality of data abstraction?

Data abstraction refers to providing only essential information to the outside world and hiding their background details, i.e., to represent the needed information in program without presenting the details.

Which keywords Cannot be used for a class which has been declared final?

Explanation: A abstract class is incomplete by itself and relies upon its subclasses to provide a complete implementation. If we declare a class final then no class can inherit that class, an abstract class needs its subclasses hence both final and abstract cannot be used for a same class.

What is the real time example of encapsulation?

Another example of encapsulation is a capsule. Basically, capsule encapsulate several combinations of medicine. If combinations of medicine are variables and methods then the capsule will act as a class and the whole process is called Encapsulation.

What is the difference between abstraction and encapsulation?

Abstraction is the method of hiding the unwanted information. Whereas encapsulation is a method to hide the data in a single entity or unit along with a method to protect information from outside. … In abstraction, implementation complexities are hidden using abstract classes and interfaces.

Which keyword is used to inherit properties from one class into another?

extendsextends is the keyword used to inherit the properties of a class. Following is the syntax of extends keyword.

What is abstraction example?

Abstraction means displaying only essential information and hiding the details. Data abstraction refers to providing only essential information about the data to the outside world, hiding the background details or implementation. Consider a real life example of a man driving a car. … This is what abstraction is.

What are three levels of data abstraction?

There are mainly three levels of data abstraction:Internal Level: Actual PHYSICAL storage structure and access paths.Conceptual or Logical Level: Structure and constraints for the entire database.External or View level: Describes various user views.

Which method Cannot be overridden?

A method declared final cannot be overridden. A method declared static cannot be overridden but can be re-declared. If a method cannot be inherited, then it cannot be overridden. A subclass within the same package as the instance’s superclass can override any superclass method that is not declared private or final.