MATLAB: Editing in string array

Question

a={'10','7','5','9','11','12','12','4'}

I want to put 0 at the starting of all those whose length is 1. How can I do this easily?

Answer 1

a={'10','7','5','9','11','12','12','4'} ;
L = cellfun(@length,a) ;
idx = L==1 ;
a(idx) = strcat('0',a(idx)) ;