Beginners Guide To Java And OOPS

Java is an object-oriented, general-purpose programming language that allows programmers to write code once and run it anywhere without the need to recompile it. It was created in May of 1995 by James Gosling. Java is now used to build smartphone and web apps, as well as games, web servers, and other applications. Java is used by NASA World Wind, Spotify, Twitter, Google, and a slew of other companies.

In this tech-driven world, learning Java opens the door to new and exciting opportunities! And guess what, it is simple to learn and is useful universally.

So what are you waiting for? Begin your journey of learning Java Programming language with us.

Variables in Java Programming

Variables in a programming language refer to the basic units of storage. Java has three types of Variables

1. Local Variables

2. Instance Variables

3. Static Variables

Data Types

In Java Programming, Data-type is primarily of two types: Primitive and Non-Primitive. The eight Primitive data types of Java define standard value's size and type. They are pre-defined and stored in a stack. Non-primitive data types, on the other hand, are defined by the users, with reference variables stored in the stack and the original object in the heap.

The eight Primitive Data Types are further divided into two types namely integer and floating-point types. Integer types consist of int, short, long, and byte. It stores whole numbers, positive or negative excluding decimals. Numbers with a fractional part and one or more decimals are expressed by floating-point types. It consists of a float and double. Boolean and character are the other data types of primitive form.

Non-Primitive Data Types are arrays, strings, objects, etc. Since the variable value will not be stored directly in memory, it will contain a memory address of the variable value. Non-Primitive Data Type is called a Reference Data Type.

Strings: An array of characters is known as a string. A character array is a list of different char-type entities. A string is immutable, however, you may make a mutable string with the StringBuffer and StringBuilder classes. In Java, the String literal and the new keyword are the two methods for creating a string.

Arrays: A set of similar types of data is referred to as an array. The allocation of all arrays is dynamic in Java Programming Language. We can also loop through the array's elements. Furthermore, Java permits multidimensional arrays. An array of arrays is a multidimensional array. To put it another way, each component of a multidimensional array is an array in and of itself.

Know how to declare and access Arrays and Strings in Java by watching the session below:

The Object-Oriented Programming System (OOPs) is a programming paradigm that builds programmes using classes and objects. It entails a number of concepts that make software creation and maintenance easier. OOPs, enable more precise simulations of real-world events. Using OOPS in Java allows you to create completely reusable applications with less code and less time spent on development. Object, class, method, and instance are the terms used while operating OOPS.

Object: It's a class's working unit.

Class: This is the blueprint or pattern for an object's capability.

Method: It can change the state of a class that applies all instances of the class.

Instance: A class is represented by an instance variable. These are declared outside of a method, constructor, or any other block in a class.

Want to learn about the OOPS in a practical form?

Watch and practice from the video below:

The four pillars of the Object-Oriented Programming System in the Java programming language are Inheritance, Polymorphism, Abstraction, and Encapsulation.

Inheritance: Inheritance permits one object to gain access to another's properties and methods. Inheritance in Java Programming language lets you reuse and create new classes that are built upon existing classes. Single, Multilevel, and Hierarchical, are three types of inheritance in Java.

​Polymorphism: Polymorphism refers to different forms of an object. Polymorphism enables you to build a single interface with multiple implementations. The two types of polymorphism in Java are compile-time and Runtime polymorphism.

​Abstraction: Abstraction is a pillar of OOPS that presents only important data to the user while hiding irrelevant information about the object.

​Encapsulation: It's a mix of data obfuscation and abstraction. Encapsulation is the process of encapsulating data into a single object. It's the process that connects code and the data it works with.

Understand each of the four pillars of the Object-Oriented Programming System in Java from an expert in the video below with real-time examples.

Are you looking forward to learning more? Enroll in the Beginners Guide to Java and OOPS course at Newton School Launchpad for free and with exciting assignments with Pratik Bhattacharya. Not only that, you can clarify your doubts and get a certificate after completion. Register now!

Pratik Bhattacharya is a senior software engineer at Microsoft and is passionate about technology and constantly works on multiple projects.