add character cells arrays

we have a character cell [d d d d] and [d -d d -d]. how can we get [d+d d-d d+d d-d].

Answer 1

[Walter Roberson]

first = {'d', 'd', 'd', 'd'};
second = {'d', '-d', 'd', '-d'};

result = regexprep(strcat(first(:), {'+'}, second(:)), '+-', '-').' ;