stored character string to character matrix by using loop

I am going to use loop to prompt out 4 course name as 5-character string as form'AB101'. And I need to stored those string in a character matrix course.

n=4;
for i = 1:n
    class{i} = input('Enter the course name : ','s')
    mymat = [ 'myDataFile' str2num(class{:}) '.mat' ];
    save(mymat);
end

str2num('class')

Here, I saved those 4 course by 4 mat file, however, how can I store in one file and switch them to a character matrix?