Summing the Digits of a Number

Question

Challenge

• Given a non-negative integer, find the sum of its decimal digits.

Rules

• Your program must take a non‐negative integer as input.
• Your program should output the sum of the digits of the input integer.
• Your program should be able to handle inputs up to 10¹⁰⁰.

Examples

• If the input is 123, the output should be 6 (1 + 2 + 3).
• If the input is 888, the output should be 24 (8 + 8 + 8).
• If the input is 1024, the output should be 7 (1 + 0 + 2 + 4).
• If the input is 3141592653589793238462643383279502884197169399375105820974944592, the output should be 315.

Format

• Your program should take input from standard input (stdin) and output the result to standard output (stdout).
• Your program should be runnable in a UNIX‐like environment.

Test cases

input	output
123	6
888	24
1024	7
3141592653589793238462643383279502884197169399375105820974944592	315

Scoring

• This is a code‐golf challenge, so the shortest code (in bytes) wins.

Answer 1

J, 13 bytes

[: +/ 48 -~ a. I. ]

Answer 2

I saw this and just had to give it a go with Java. I mean, I'm not going to win, but it's in good fun, right? Using loops, assuming that we can have multiple inputs, including 0:

class D{public static void main(String[]a){int s=0;for(String t:a)for(char c:t.toCharArray())s+=c-48;System.out.println(s);}}

That gives 125 bytes, but if we assume some assumptions, we can surely get it lower. If we assume one and only input, we don't have to loop, so we can shorten it down further. But if we also stream, we get:

class D{public static void main(String[]a){System.out.println(a[0].chars().map(i->i-48).sum());}}

Which clocks in at 97 bytes.

That's not too bad for Java.

Answer 3

vemf, 6 bytes

ª-:48+

Input is a number literal.

try it online, uses :314159 as example

Explanation

ª      ' represent as a codepage string
 -:48  ' subtract 48 from each codepoint
       ' (so the codepoints are all now 0-9)
     + ' sum list

Answer 4

Java 8 (OpenJDK 8), 31 bytes

Very classic answer in Java

s->s.chars().map(e->e-48).sum()

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Answer 5

Python, 42 Bytes

lambda x:sum(int(y) for y in list(str(x)))

Try this code online

Answer 6

C# (Visual C# Interactive Compiler), 18 bytes

s=>s.Sum(a=>a-48);

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Answer 7

Python 3, 33 (35!) 30 bytes

-5 thanks to c--. No strings

f=lambda n:n and n%10+f(n//10)

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Answer 8

Bash & coreutils, 21 bytes

fold -1|paste -sd+|bc

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Answer 9

Thunno 2 S, 0 bytes

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No bytes, that's right.

Thunno 2, 1 byte

S

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Alternatively, have a built-in.

Answer 10

Java, 27 bytes

for(s=0;n>0;s+=n%10,n/=10);

Input as Integer (n)

Answer 11

Swift, 51 bytes

let s={String($0+0).reduce(0){Int("\($1)")!+$0}}

Answer 12

Perl 5 -MList::Util=sum -pF, 8 bytes

$_=sum@F

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Answer 13

Setanta, 57 bytes

gniomh(n){s:=0le i idir(0,fad@n)s+=go_uimh(n[i])toradh s}

try-setanta.ie link

Version for native number type (up to \$2^{53}\$), 35 bytes

gniomh f(n){toradh n&n%10+f(n//10)}

try-setanta.ie link

Answer 14

Clojure, 42 bytes

#(apply +(map parse-long(map str(str %))))

Answer 15

Uiua, 6 bytes

/+∵⋕°⋕

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Explanation:

/+∵⋕°⋕
  ∵⋕°⋕ => number to list of each digit
/+     => sum