cc = cellfun(@num2str,c,'uni',0)
if you have both string and numerics in cell array and you want to convert them all to char,
cc = cell(size(c));
for k=1:numel(c)
if(isnumeric(c{k}))
cc{k} = num2str(c{k});
elseif (isstring(c{k}))
cc{kk}= char(c{k});
%and so on
end
end
Another idea is,
cellfun(@(x) char(string(x)),c,'uni',0)
