Where java can be used?

➖JAVA program is used in, Mobile applications, Stand alone applications, dynamic applications and BigData(Hadoop) technology.

1. Standalone Applications:-

➖An application which never utilizes external resources for execution, it is known as standalone applications.

Ex: Calculators, music players, parking meters, etc.

2. Dynamic Applications:-

➖An application which utilizes external resources for execution, it is known as dynamic application.

➖External resources are like server facility, internet connectivity and database utilization.

➖Dynamic applications are also also known as server side app or web applications.

Ex: Amazon, Flipkart(e-commerce) etc.

☆Class body:-

➖After class declaration, open in curly braces and closed curly braces represent class body.

➖In a class body, programmer can be declare data members, member functions, blocks and constructor.

➖If programmer want to declare any executable statements then those statements need to be declared inside class body.

➖Declaring executable statements outside class body throws error.

(It is because of Encapsulation rule).

☆Main method:-

➖Main method places very important role in execution of java program because of main method is the entry point of Java program.

➖Without main method compilation takes place but execution don't.

Ex:-

class Demo

{

   public static void main(String [] args)

   {

      System.out.println("Hello");

   }

}

javac Demo.java

java Demo

O/p:- Hello

☆print:-

➖Prints the output and the cursor remains in the same line.

☆println:-

➖Prints the output and the cursor jumps to the next line.

Ex:-

class Demo1

{

   public static void main(String [] args)

   {

      System.out.print("Hello all");

      System.out.println("Hello");

   }

}

javac Demo1.java

java Demo

O/p:- Hello allHello

System.out.println("HI");

HI

System.out.println(2);

2

System.out.println("HI+HELLO");

HI+HELLO

System.out.println("2+2");

2+2

System.out.println(2+2);

4

System.out.println("hi"+"hello");

hihello

System.out.println("hi"+"hello"+"2+2");

hi+hello2+2

System.out.println(2+2+"hi");

4hi

System.out.println("hi"+2+2);

Hi22

System.out.println(2+2+"hi"+2+2);

4hi22

System.out.println("hi"+(2+2));

hi4