MATLAB: Display a message only one time in a recursion containing a for loop

for looprecursion

Consider this simple code
a=[1 1 0 1];
recursion(a)
with
function a=recursion(a)
    if isempty(a)
        disp('a does not contain 0')
    else
         for i=1:numel(a)
            if a(1)==0
                disp('a contains 0')
                return
            end
            a=a(2:end);
            recursion(a);
         end
    end
end
Don't focus on the aim of the code (of course the job could be done in 1 line or 2) but on the output
a contains 0
a contains 0
a contains 0
a contains 0
ans =
       0     1
Is it possibile to output the message "a contains 0" only one time AND then to output the modified vector "a" ? i.e. is it possibile to have this output
a contains 0
ans =
       0     1

Best Answer

Do not have recursion return a, since the changed value is not used. Instead, have it return a status as to whether it encountered a 0. Check the output and if set then break out the the loop and return 1. Only return 0 if you get to the end of the loop without a 0.
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