Sum of Digits on Java

 Sum of Digits ka mtlb hota hai  integer ke digits ko add krna 

Example 123
1+2+3 =6

package learning;

import java.util.Scanner;

public class learnNew {

public static void main(String[] args){

Scanner scan = new Scanner(System.in) ;

int n = scan.nextInt();

int sum = 0;

while(n > 0) {

int r = n % 10;

sum = sum + r;

n = n/10 ;

}

System.out.println(sum);

}

}

Step:

• hamne yaha while loop ka use kiya hai aap chahe to for loop ka bhi istemal kr skte hai 
  for loop for  this>>   
  

  for(;n > 0;) { //this is syntax of for loop

• sbse phle while loop check karega kya n (123) > a ... n bdha hai 0 se agr han to condition true hoga aur loop me enter  hoga
• ab loop  ke andar ki  statement check hogi 
• n  ko 10 se modulus karenge n % 10 [ modulus ham isliye  use kr rhe kyo ki modulus sirf remainder deta hai . 
  
  
  
  
  
  
  
• Remainder 3 aayega aur wo save ho jayega r variable me .
• uske bad ham sum = sum + r kar rhe ...  sum phle 0 tha lekin r hamare pass 3 aaya hai to ab previous sum 0 + r (remainder) 3 add hoga  aur sum bnega 3.
• n = n / 10; isse n jo 126 tha use 10 se divide karenge jisse hame 12 milega aur ab hamara n 12 ho chuka hai
  
  
  
  
  
• dubara loop check karega kya n (12) > 0 se bdha hai agar han to dubara 12 % 10 karega
  
  
  
  
  
•  ab r me 2 remainder aa chuka hai jo ki  r me store ho jayega.
• sum =  sum + 2  me phle sum hamara 3 tha ab 3  +  2 hoga 5 .
• ab 5  dubara se jake sum me add ho jayega aur ab sum ki value 5 ho chuki hai .
• hamara n jo ki last me 12 tha ab dubara se 10 se divide kiya jayega jitni bar me divide hoga wo dubara se n me jake  store ho jayega 
• 12 ko ham 10 se divide krenge to 1 se divide hoga aur remainder 2 milega mtlb hamara n ab 1 ho chuka hai .
• dubara loop me aayega aur check karega kya n (1) 0 se bdha hai han ek se bdha hai , ha 1 , 0  se bdha hai to loop true hoga aur statement check karega .
• r = n %  10 n hamara 1 hai ek ko 10 se divide karenge to remainder 1 hi aayega aur divide hoga 0.1 times
• lekin kyu ki n ki value int li gyi hai to n hamara ab 0 ho chuka hai , ye float me save nhi  hoga  
• aur remainder hamara 1 aaya tha jo ki sum me add ho jayega
• now 2+3+1 sum me store ho chuka hai ab ham sum ko print krenge to sum of digit ho jayega answer aayega 6 .