What is magic number in java ?

A number is said to be magic number if the repetitive sum of digits of number is equal to 1 or a single digit number . If the repetitive sum ends up  as 1 then the number is a magic number, else not.

For example-

n= 289;.   2+8+9 = 19

     19;.      1+9 = 10

     10;.      1+0= 0

      1

Since the number ends in 1, hence 289 is a magic number.

Magic number in java is the java program to check whether a number is magic number or not .

For this we do repetitive addition of the digits of the number till the number is a two or more digit number.

If after repetitive adding digits of the number ends up to 1 then the loop stops and a message is displayed.

For this program we need to extract digits of the number for this we use while loop and add this digit .

Code snippet to get digits of the number -

while(n!=0)

{

       int d = n%10;

        s=s+d;

       n=n/10;

}

ALGORITHM-

STEP 1: start STEP 2: print "enter a number" STEP 3: taking input of integer in n STEP 4: repeat STEP 5 to STEP 10 until n>9 STEP 5: int s=0 STEP 6: repeat STEP 7 to STEP 9 until n!=0 STEP 7: int d=n%10 STEP 8: s=s+d STEP 9: n=n/10 STEP 10:n=s STEP 11:if n==1 then goto STEP 12 else goto STEP 13 STEP 12:print "it is a magic number STEP 13:print " it is not a magic number STEP 14:end

Java code- 

import java.util.*;

public class magic

{

public static void main()

{

Scanner sc=new Scanner(System.in);

  System.out.println("enter a number");

  int n=sc.nextInt();

while(n>9)

{

int s=0;

while(n!=0)

{

int d=n%10;

s=s+d;

n=n/10;

}

n=s;

}

if(n==1)

{

System.out.println("it is a magic number");

}

else

{

System.out.println("it is not a magic number");

 }

}

}

Output-

enter a number

289

It is a magic number

similar java codes

1-Prime number

2-Palindrome number

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