Program for Sum of the digits of a given number

Given a number, find sum of its digits.

Examples :

Input : n = 687
Output : 21

Input : n = 12
Output : 3

Recommended: Please solve it on “PRACTICE ” first, before moving on to the solution.

General Algorithm for sum of digits in a given number:

Get the number
Declare a variable to store the sum and set it to 0
Repeat the next two steps till the number is not 0
Get the rightmost digit of the number with help of remainder ‘%’ operator by dividing it with 10 and add it to sum.
Divide the number by 10 with help of ‘/’ operator
Print or return the sum

Below are the solutions to get sum of the digits.
1. Iterative:

C++

// C program to compute sum of digits in  
// number. 
# include<iostream> 
using namespace std; 
/* Function to get sum of digits */
class gfg 
{ 
    public: 
    int getSum(int n) 
    {  
    int sum = 0; 
    while (n != 0) 
    { 
     sum = sum + n % 10; 
     n = n/10; 
    }  
 return sum; 
 } 
}; 
//driver code 
int main() 
{ 
 gfg g; 
 int n = 687; 
 cout<< g.getSum(n); 
 return 0; 
} 
//This code is contributed by Soumik 

C

// C program to compute sum of digits in  
// number. 
# include<stdio.h> 
  
/* Function to get sum of digits */
int getSum(int n) 
{  
   int sum = 0; 
   while (n != 0) 
   { 
       sum = sum + n % 10; 
       n = n/10; 
   } 
   return sum; 
} 
  
int main() 
{ 
  int n = 687; 
  printf(" %d ", getSum(n)); 
  return 0; 
} 

Java

// Java program to compute  
// sum of digits in number. 
import java.io.*; 
  
class GFG { 
      
    /* Function to get sum of digits */
    static int getSum(int n) 
    {     
        int sum = 0; 
          
        while (n != 0) 
        { 
            sum = sum + n % 10; 
            n = n/10; 
        } 
      
    return sum; 
    } 
  
    // Driver program 
    public static void main(String[] args) 
    { 
        int n = 687; 
  
        System.out.println(getSum(n)); 
    } 
} 
  
// This code is contributed by Gitanjali 

Python3

# Python 3 program to 
# compute sum of digits in  
# number. 
  
# Function to get sum of digits  
def getSum(n): 
   
    sum = 0
    while (n != 0): 
      
        sum = sum + int(n % 10) 
        n = int(n/10) 
      
    return sum
  
n = 687
print(getSum(n)) 

C#

// C# program to compute  
// sum of digits in number. 
using System; 
  
class GFG 
{ 
    /* Function to get sum of digits */
    static int getSum(int n) 
    {  
        int sum = 0; 
          
        while (n != 0) 
        { 
            sum = sum + n % 10; 
            n = n/10; 
        } 
      
    return sum; 
    } 
  
    // Driver program 
    public static void Main() 
    { 
        int n = 687; 
        Console.Write(getSum(n)); 
    } 
} 
  
// This code is contributed by Sam007 

PHP

<?php 
// PHP Code to compute sum  
// of digits in number. 
  
// Function to get  
// $sum of digits  
function getsum($n) 
{  
    $sum = 0; 
    while ($n != 0) 
    { 
        $sum = $sum + $n % 10; 
        $n = $n/10; 
    } 
    return $sum; 
} 
  
// Driver Code 
$n = 687; 
$res = getsum($n); 
echo("$res"); 
  
// This code is contributed by  
// Smitha Dinesh Semwal. 
?> 

Output :

How to compute in single line?
Below function has three lines instead of one line but it calculates sum in line. It can be made one line function if we pass pointer to sum.

C++

# include<iostream> 
using namespace std; 
/* Function to get sum of digits */
class gfg 
{ 
 public: 
 int getSum(int n) 
 { 
    int sum; 
  
    /* Single line that calculates sum */
    for (sum = 0; n > 0; sum += n % 10, n /= 10); 
  
    return sum; 
 } 
}; 
  
//driver code 
int main() 
{ 
 gfg g;    
 int n = 687; 
 cout<< g.getSum(n); 
 return 0; 
} 
//This code is contributed by Soumik 

C

# include<stdio.h> 
/* Function to get sum of digits */
int getSum(int n) 
{ 
    int sum; 
  
    /* Single line that calculates sum */
    for (sum = 0; n > 0; sum += n % 10, n /= 10); 
  
    return sum; 
} 
  
int main() 
{ 
  int n = 687; 
  printf(" %d ", getSum(n)); 
  return 0; 
} 

Java

// Java program to compute 
// sum of digits in number. 
import java.io.*; 
  
class GFG { 
      
    /* Function to get sum of digits */
    static int getSum(int n) 
    { 
        int sum; 
  
        /* Single line that calculates sum */
        for (sum = 0; n > 0; sum += n % 10, 
                                  n /= 10); 
  
        return sum; 
    } 
  
    // Driver code 
    public static void main(String[] args) 
    { 
        int n = 687; 
  
        System.out.println(getSum(n)); 
    } 
} 
  
// This code is contributed by Gitanjali 

Python3

# Function to get sum of digits  
  
def getSum(n): 
  
    sum = 0
  
    # Single line that calculates sum  
    while(n > 0): 
        sum += int(n%10) 
        n = int(n/10) 
  
    return sum
  
# Driver code 
  
n = 687
print(getSum(n)) 
  
# This code is contributed by 
# Smitha Dinesh Semwal 

C#

// C# program to compute  
// sum of digits in number. 
using System; 
  
class GFG 
{ 
    static int getSum(int n) 
    { 
        int sum; 
  
        /* Single line that calculates sum */
        for (sum = 0; n > 0; sum += n % 10, 
                                n /= 10); 
  
        return sum; 
    } 
  
    // Driver code 
    public static void Main() 
    { 
        int n = 687; 
        Console.Write(getSum(n)); 
    } 
} 
  
// This code is contributed by Sam007 

PHP

<?php 
// PHP Code for Sum the  
// digits of a given number 
  
// Function to get sum of digits  
function getsum($n) 
{ 
  
    // Single line that calculates $sum 
    for ($sum = 0; $n > 0; $sum += $n % 10,  
                                  $n /= 10); 
    return $sum; 
} 
  
// Driver Code 
$n = 687; 
echo(getsum($n)); 
  
// This code is contributed by  
// Smitha Dinesh Semwal. 
?> 

Output :

2. Recursive
Thanks to ayesha for providing the below recursive solution.

C++

#include<iostream> 
using namespace std; 
class gfg 
{ 
 public: int sumDigits(int no) 
 { 
   return no == 0 ? 0 : no%10 + sumDigits(no/10) ; 
 } 
}; 
  
//driver code 
int main(void) 
{ 
    gfg g; 
    cout<<g.sumDigits(687); 
    return 0; 
} 

C

int sumDigits(int no) 
{ 
   return no == 0 ? 0 : no%10 + sumDigits(no/10) ; 
} 
  
int main(void) 
{ 
    printf("%d", sumDigits(687)); 
    return 0; 
} 

Java

// Java program to compute 
// sum of digits in number. 
import java.io.*; 
  
class GFG { 
    
    /* Function to get sum of digits */ 
    static int sumDigits(int no) 
    { 
        return no == 0 ? 0 : no%10 +  
                  sumDigits(no/10) ; 
    } 
  
    // Driver code 
    public static void main(String[] args) 
    { 
    System.out.println(sumDigits(687)); 
    } 
} 
  
// This code is contributed by Gitanjali 

Python3

# Python program to compute 
# sum of digits in number. 
  
def sumDigits(no): 
    return 0 if no == 0 else int(no%10) + sumDigits(int(no/10))  
  
# Driver code 
print(sumDigits(687)) 
  
# This code is contributed by 
# Smitha Dinesh Semwal 

C#

// C# program to compute  
// sum of digits in number. 
using System; 
  
class GFG 
{ 
    /* Function to get sum of digits */
    static int sumDigits(int no) 
    { 
        return no == 0 ? 0 : no % 10 +  
                sumDigits(no / 10); 
    } 
  
    // Driver code 
    public static void Main() 
    { 
        Console.Write(sumDigits(687)); 
    } 
} 
  
// This code is contributed by Sam007 

PHP

<?php 
// PHP program to compute  
// sum of digits in number. 
function sumDigits($no) 
{ 
return $no == 0 ? 0 : $no % 10 +  
                      sumDigits($no / 10) ; 
} 
  
// Driver Code 
echo sumDigits(687); 
  
// This code is contributed by aj_36 
?> 

Output :

Please write comments if you find the above codes/algorithms incorrect, or find better ways to solve the same problem.

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My Personal Notes

Recommended: Please solve it on “PRACTICE ” first, before moving on to the solution.

C++

C

Java

Python3

C#

PHP

C++

C

Java

Python3

C#

PHP

C++

C

Java

Python3

C#

PHP

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