# I want to write a recursive Function that can calculate the sum of all the digit. If the input is 12345 then the answer will be 1+2+3+4+5 , without using string2num and loop.

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Asif Ahmed on 17 Aug 2020
Answered: Farhath Surayya on 19 Nov 2020
function output= digit_sum(n)
if n<10
output=fix(n);
end
if n>0
output=output+digit_sum(n*0.1);
end
end
I wrote this code but the problem I am facing is if i set output=0; anywhere then in all the recalling function process my result will turn to be 0, How to Solve this ?
Asif Ahmed on 17 Aug 2020

David Hill on 17 Aug 2020
function output= digit_sum(n,a)
if nargin==1
a=0;
end
if n<10
output=a+fix(n);
else
output=digit_sum(floor(n*.1),a+mod(n,10));
end
end
Asif Ahmed on 17 Aug 2020
function output= digit_sum(n)
if n<10
output=fix(n);
end
if n>0
output=((n/10 -fix(n/10))*10)+digit_sum(fix(n*0.1));
end
end
Thanks , I got the problem where i was mistaking,Now the code runs fine. Thanks for your help.
function output= digit_sum(n)
if n<10
output=fix(n);
end
if n>0
output=mod(n,10)+digit_sum(fix(n*0.1));
end
end

Saptarshi Neogi on 30 Aug 2020
You can do this with any inbuit functions.
function x = digit_sum(n)
x=0;
if n>0
x=mod(n,10)+digit_sum(floor(n./10));%recursive
end

Sanjay Raju on 13 Sep 2020
function x=digit_sum(inp)
if inp<10
x=inp;
else
x = mod(inp,10) + digit_sum(fix(inp/10));
end
end

Farhath Surayya on 19 Nov 2020
function output= digit_sum(n) if n<10 output=fix(n); end if n>0 output=output+digit_sum(n*0.1); end end