Skip to main content

OOP concepts in Java





What is the Class? 
The class is a group of similar entities. It is extensible program code for creating objects and to define data types as well as methods.

What is Object in OOP?
Object refers to a particular instance of a class whereas objects can be a combination of variables, functions and data structures.

What are the 4 principles in OOP?
Encapsulation, Data Abstraction, Polymorphism and Inheritance.

What is Inheritance?
Deriving a new class from an existing class and forming them into a hierarchy of classes.

What is Encapsulation? 
 It is used to hiding the implementation details.

What is Constructor overloadin? 
It is a feature that allows a class to have more than one constructor having different argument lists.

What is the difference between method overloading vs method overriding?



Why do we need to use Method Overloading?
Suppose that you have a class that can use calligraphy to draw various types of data (strings, integers, and so on) and that contains a method for drawing each data type. It is difficult to use a new name for each method—for example, drawString, drawInteger, drawFloat, and so on.

In the Java programming language, you can use the same name for all the drawing methods but pass a different argument list to each method. Thus, the data drawing class might declare four methods named draw, each of which has a different parameter list.

public class DataArtist {
    ...
    public void draw(String s) {
        ...
    }
    public void draw(int i) {
        ...
    }
    public void draw(double f) {
        ...
    }
    public void draw(int i, double f) {
        ...
    }
}

Why do we need to use Method Overriding?  

Declaring a method in the subclass which is already present in the parent class is known as method overriding. Overriding is done so that a child class can give its own implementation to a method which is already provided by the parent class.

The implementation in the subclass overrides (replaces) the implementation in the superclass by providing a method that has the same name, same parameters or signature, and same return type as the method in the parent class. The version of a method that is executed will be determined by the object that is used to invoke it. If an object of a parent class is used to invoke the method, then the version in the parent class will be executed, but if an object of the subclass is used to invoke the method, then the version in the child class will be executed.

  1. Helps in writing generic code based on parent class or interface as object resolution happens at runtime
  2. Provides multiple implementations of the same method and can invoke parent class overridden method using super keyword
  3. Defines what behaviour a class can have and implementation of behaviour has been taken care by a class which is going to implement.



Labels:

Comments

Post a Comment

Popular posts from this blog

Regularization in Deep Learning / Machine Learning - Prevent Overfitting

image source: mlexplained Overfittng happens in every machine learning (ML) problem.  Learning how to deal with overfitting is essential to mastering machine learning.  The fundamental issue in machine learning is the tension between optimization  and generalization. Optimization refers to the process of adjusting a model to get the  best performance possible on the training data (the learning in machine learning ),  whereas generalization refers to how well the trained model performs on data it has  never seen before . The goal of the game is to get good generalization, of course, but you don’t control generalization; you can only adjust the model based on its training  data.  The processing of fighting overfitting is a way  called regularization . [1].  How do you know whether a model is overfitting? The best initial method is to measure error on a training and test set. If you see a low error on the training set and...
1 comment
Read more

A Brief Overview of GPT-3 by OpenAI

    You have probably already seen some articles like "A robot wrote an entire article. Aren't you scared yet, human?" So, who is the robot here?    It's GPT-3 model. It's a transformer based language model. The full form of GPT is Generative Pre-trained Transformers. This model is developed by OpenAI. There were GPT-2 and other models released by OpenAI previously. GPT-3 was released in May 2020. GPT-3 is more robust than its predecessors. Though architecturally it doesn't have that mush difference.   GPT-3 can write articles, poems, and even working code for you*, given some context. There are some limitations which I am going explain later in this article. It's a language model means given a text, it probabilistically predicts what tokens from a known vocabulary will come next in that string. So, it's sort of a autocomplete that we see on a phone keyboard. We type a word, and then the keyboard suggests another word that can come next. What sets GPT...
1 comment
Read more

Lambda, Map, and Filter in Python

Lambda: Lambda functions are known as the anonymous functions in Python. This kind of functions are declared without any name. Can accept any number of argument.  Restricted to only a single expression.  Used only one-time. Lambda function is used when you need a function for a short period of time.  Basic syntax:  lambda arguments : expression Example: Map: Map is a built-in function that takes a function object and iterable list (list/dictionary) as its parameter. Basic syntax: map (function_object, iterable_1, iterable_2, ... ) Few examples of Map in python: Filter: It works similar way like map. The difference is it makes a new list from the element in the list that satisfy some condition . In case of of parameters, it takes a function and one iterable. Basic syntax: filter (function, iterable) Normally used with lambda functions. Example is given below:
2 comments
Read more