HashMap in java

package com.home;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;

public class HashMapDemo1 {
   
public static void main(String[] args) {
Map<Integer, String> a = new HashMap<Integer, String>();

a.put(1, "hari");
a.put(2, "Gopal");
a.put(3, "RAm");
a.put(4, "Mohan");
a.put(5, "Daro");

int size = a.size();

System.out.println(size);


a.remove(1);
System.out.println(a);

Set set = a.entrySet();

Iterator it = set.iterator();

while(it.hasNext()){

Map.Entry me = (Map.Entry) it.next();

System.out.println("This is key = "+me.getKey()+" : "+"This is value "+me.getValue());
}
}
}
The Output of the Following Program is:

5
{2=Gopal, 3=RAm, 4=Mohan, 5=Daro}
This is key = 2 : This is value Gopal
This is key = 3 : This is value RAm
This is key = 4 : This is value Mohan
This is key = 5 : This is value Daro

Java program to check ArmStrong Number

Java program to check ArmStrong Number:

package javaapplication1;
import java.util.*;

public class ArmStrongNumber {
    public static void main(String args[])
   {
      int n, sum = 0, og, r;

      Scanner in = new Scanner(System.in);
      System.out.println("Enter a number to check if it is an armstrong number");     
      n = in.nextInt();

      og = n;

      while( og != 0 )
      {
         r = og%10;
         sum = sum + r*r*r;
         og = og/10;
      }

      if ( n == sum )
         System.out.println("Entered number is an armstrong number.");
      else
         System.out.println("Entered number is not an armstrong number.");        
   }
}

Java BizzBuzz Program

package javaapplication22;


public class BizzBuzzDemo {
   
    public static void main(String[] args) {
        for(int i=1;i<=50;i++){
            if(i%3==0){
                System.out.println("Bizz"+i);
            }else if(i%5==0){
                System.out.println("Buzz"+i);
            }else if(i%3==0 && i%5==0){
                System.out.println("BizzBuzz"+i);
            }else{
                System.out.println(i);
            }
       
        }
    }
}

OUTPUT:

1

2

Bizz3

4

Buzz5

Bizz6

7

8

Bizz9

Buzz10

11

Bizz12

13

14

Bizz15

16

17

Bizz18

19

Buzz20

Bizz21

22

23

Bizz24

Buzz25

26

Bizz27

28

29

Bizz30

31

32

Bizz33

34

Buzz35

Bizz36

37

38

Bizz39

Buzz40

41

Bizz42

43

44

Bizz45

46

47

Bizz48

49

Buzz50

java hello world program

// java hello world program
 public class HelloWorld{

public Static void main(String[] arg){
System.out.println("Hello world");
}
}

Simple Java Program to calculate Restaurant Bill

package restaurants;

import java.util.Scanner;


public class Restaurants {

    
    public static void main(String[] args) {
        
        Scanner input = new Scanner(System.in);
        boolean quit= false;
        int sum=0;
        int wine=200,cold=20,bear=400,juice=100;
        String order="";
        
        do{
            System.out.println("ITEM"+"\t\tPrice");
            System.out.println("1.Wine"+"\t\t"+"200");
            System.out.println("2.ColdDrink"+"\t"+"20");
            System.out.println("3.Bear"+"\t\t"+"400");
            System.out.println("4.Juice"+"\t\t"+"100");
            System.out.println("5.Quit");
            
            int choice=input.nextInt();
            
            switch(choice){
                case 1:System.out.println("Wine"+"\n");
                        sum=sum+wine;
                        order=order.concat("wine"+"\n");
                        
                    break;
                case 2:
                    System.out.println("ColdDrink");
                    sum=sum+cold;
                    order=order.concat("ColdDrink"+"\n");
                    
                       break;
                case 3:
                    System.out.println("Bear");
                    sum=sum+bear;
                    order=order.concat("Bear"+"\n");
                      break;
                case 4:
                    System.out.println("Juice");
                    sum=sum+juice;
                    order=order.concat("Juice"+"\n");
                    break;
                case 5:
                     quit=true;
                     
                    break;
                default:
                    System.out.println("Wrong input");
            }
        
        }while(!quit);
       
        System.out.println("Your Orders are:\n"+order);
        System.out.println("Your total bill="+sum);
        
         System.out.println("Thank you");
    
        
        
        
    
    }
    
}

OUTPUT:

ITEM Price
1.Wine 200
2.ColdDrink 20
3.Bear 400
4.Juice 100
5.Quit
1
Wine

ITEM Price
1.Wine 200
2.ColdDrink 20
3.Bear 400
4.Juice 100
5.Quit
2
ColdDrink
ITEM Price
1.Wine 200
2.ColdDrink 20
3.Bear 400
4.Juice 100
5.Quit
3
Bear
ITEM Price
1.Wine 200
2.ColdDrink 20
3.Bear 400
4.Juice 100
5.Quit
4
Juice
ITEM Price
1.Wine 200
2.ColdDrink 20
3.Bear 400
4.Juice 100
5.Quit
5
Your Orders are:
wine
ColdDrink
Bear
Juice

Your total bill=720