How to use Javadoc Comments in Java program for Documentation ?

Program to use Javadoc Comments in Java for Documentation

/**
 * @see java.util.Date
 * */
import java.util.Date;


/** A simple program demonstrating
 * Java Documentation by placing following 
 * annotations :   
 * @author Jonty
 * @author www.hubberspot.com
 * @version 3.0 
 * */
public class TodaysDate {

/**Entry to main method that prints 
 * todays date. 
 * @param args
 * @exception throws no exceptions
 */
   public static void main(String[] args) {
      System.out.println("Hello, it’s: ");
      System.out.println(new Date());

   }

}

Usage command :
javadoc TodaysDate.java

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How to print System Properties through a Java program ?

Program to print System Properties through a Java

public class SystemProperties {

   public static void main(String[] args) {

      System.getProperties().list(System.out);
      System.out.println();
      System.out.println("The User Name property : ");
      System.out.println(System.getProperty("user.name"));
      System.out.println("The Java Library path property : ");
      System.out.println(System.getProperty("java.library.path"));

    }

}

Output of the program :

How to calculate BMI of body in Java ?

Program to calculate BMI of body in Java

import java.util.Scanner;

public class CalculateBMI {
  public static void main(String[] args) {
   
     final double KILOGRAMS_PER_POUND = 0.453; 
     final double METERS_PER_INCH = 0.026;   
    
     Scanner input = new Scanner(System.in);
    
     System.out.print("Enter weight in pounds: ");
     double weight = input.nextDouble();
        
     System.out.print("Enter height in inches: ");
     double height = input.nextDouble();
    
     double weightInKilogram = weight * KILOGRAMS_PER_POUND; 
     double heightInMeters = height * METERS_PER_INCH; 
     double bmi = weightInKilogram / 
      (heightInMeters * heightInMeters);
    
     System.out.printf("Your Body Mass Index is " + bmi);
    
     if (bmi < 16)
       System.out.println("You are seriously underweight");
     else if (bmi < 18)
       System.out.println("You are underweight");
     else if (bmi < 24)
       System.out.println("You are normal weight");
     else if (bmi < 29)
       System.out.println("You are overweight");
     else if (bmi < 35)
       System.out.println("You are seriously overweight");
     else
       System.out.println("You are gravely overweight");
  }
}

Output of the program :