# Can you find the error in this code that aims to sum the digits of a string?

23 views (last 30 days)
GEORGIOS BEKAS on 6 Jan 2019
Edited: Stephen23 on 6 Jan 2019
I wrote this code in order to sum the digits of any string, and to also create a loop that stops the summing process when the length of the sum is equal to a single digit.
What's wrong?
n = '12361927'
function d = sumdigits(n)
s=0
for i=1:length(n)
s=s+str2double(n(i))
end
end
s=sumdigits(n)
if length(str2num(s))==1
s=s
else
while length(str2num(s))~=1
if length(str2num(s))==1
break
else
s=sumdigits(s)
end
end
end

Stephen23 on 6 Jan 2019
Simpler:
str = '12361927'
while numel(str)>1
num = sum(str-'0')
str = num2str(num)
end
Prints this in the command window:
str = 12361927
num = 31
str = 31
num = 4
str = 4
Stephan on 6 Jan 2019
nice new knowledge

Stephan on 6 Jan 2019
Hi,
try :
n = '12361927'
s=num2str(sumdigits(n))
if strlength(s)==1
s=s;
disp('here')
else
while strlength(s)~=1
if strlength(s)==1
break
else
s=num2str(sumdigits(s))
end
end
end
function d = sumdigits(n)
s=0;
for i=1:length(n)
s=s+str2double(n(i));
end
d=s;
end

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