Introduction Java

Introduction Java

Java is an object-oriented, high-level, multi-threaded, portable, secure, platform-independent programming language. It is designed for internet and web applications. Java has widespread acceptance .Java is an object-oriented programming language.

Object-oriented programming is a programming methodology. OOPs is a method of implementation in which programs are organized as collections of objects, each of which represents an instance of some class.

OOPS Principles

Basic OOPS Principles or common jargon of Java are:

Class, Object, Encapsulation, Abstraction, Inheritance, Polymorphism

We would write a simple class in Java to print Hello World! on the console. You can choose your favorite IDE to write the program. I prefer either Eclipse or IntelliJ IDEA. We use Ecplise here to write the class code snippet.

You can create a new class from the menu shown and highlighted below :

 

Class_In_Eclipse_Java_Introduction

Sample Class

Sample class to print HelloWorld! text on the console.

public class HelloWorld
    {
    public static void main(String[] args)
       {
       System.out.println("Hello World!");
        }
}

 

To run the program choose Right click –> Run as –> Java Application

 

 Basic Jargon

Keywords are reserved identifiers that are predefined in Java language. example class, method, etc.

Identifier: A name in a program is called an identifier. An identifier may be any sequence of uppercase and lowercase letters, numbers, etc. Keep the identifier name descriptive which increases the readability and understanding of the program.

Note that: Identifiers must not begin with a number or any special character other than _ and $.

Variable: variable is the basic unit of storage in a Java program. All variables have a scope, which defines their visibility. ( private, public, protected, default )

JVM_Introduction_to_Java

 

Data types

Java is a strongly typed language. It means every variable has a type.Java has eight primitive types of data

  • byte
  • short
  • int
  • long
  • char
  • float
  • double
  • boolean

 

In conclusion, Java is very popular and knowledge is essential for automation engineers. Object-oriented programming skills make it easy to learn automation. OOPs is a method of implementation in which programs are organized as collections of objects

Related Posts