Basic Java Program with Variable Introduction and Class Introduction - Example0001

Basic Java Program with Variable Introduction and Class Introduction - Example0001 

Example1:
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This is example of a basic java program which shows structure of the program. It is basic java program showing different type of Java variables.
Primitive types: Integer, float, double, Boolean are shown
Creating an object.
Reference types and methods to that object.
How to print output in a screen is shown using System Class


package com.swprogramdeveloper;

import java.util.Date;

public class Main {

    public static void main(String[] args) {
 // write your code here
     //variable types double and integer
        double age = 30;
        int herage = (int) age + 20;
  //Printing output using System Class
        System.out.println("Hello World "+age + "---" + herage);

     //float type. Note the F- it is required as the compiler will take double as default and will show error if 'F' not given
        float viewCount= 567.23F;
        System.out.println("Float variable : " + viewCount);

     //We create a new object of Class Date using keyword 'new'
  //Object is an instance of a Class
        Date newDate1 = new Date();
  //Class will have methods, which all objects can use as per the purpose of the method
  //Date is Reference type variable and required toString method to get string to be able to print content
        System.out.println("Current Time : " + newDate1.toString());
        System.out.println("Current Time Directly : " + newDate1);

  //String is also of type Reference, but no need to create object by 'new' keyword, we can directly initialize
        String message1 = new String();
        message1 = "Hello BRO!";
        System.out.println("String : " + message1);

        //We can use many available methods of a Class
        Boolean result1 = message1.endsWith("O!");
        System.out.println("Does it contain a string ? " + result1);
        int result2 = message1.length();

       //Here we are using escape character to be able to print ' " '
      //We can concatenate string with a '+'
        System.out.println("Length of string : \"" + message1 + "\" is :" + result2);
        System.out.println("All sent to upper case for string : \"" + message1 +"\" is : " + message1.toUpperCase() );

    }
}


Output1
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Hello World 30.0---50
Float variable : 567.23
Current Time : Sat Apr 18 19:18:59 NPT 2020
Current Time Directly : Sat Apr 18 19:18:59 NPT 2020
String : Hello BRO!
Does it contain a string ? true
Length of string : "Hello BRO!" is :10
All sent to upper case for string : "Hello BRO!" is : HELLO BRO!

Process finished with exit code 0