How to return a value in a recursive function in MATLAB

I have a recursive function to calculate the multiplicative persistence of an integer. I can print the value inside the function. My question is how can I return the value to the outside of the function.

Here is my code:

I want to return the value of num

function per(n, varargin)

if nargin == 1
    num = 0;
else
    num = varargin{1};
end

s = num2str(n);
if (length(s) == 1)
    disp(['Persistence: ' num2str(num)]);
    return;
end

num = num + 1;
res = 1;
for i = 1:length(s)
    res = res * str2double(s(i));
end
per(res, num);
end

Something like num = per(n)

Answer 1

[Walter Roberson]

function num = per(n, varargin)

and at the end, probably

  num = per(res, num)

[Arindam Bose]

Wow, thanks a bunch. Works like a charm.