NaN to String Conversion in table

I have a Table in Matlab called B. In table B there is a column(6) that contains all NaN values IF the user decides to leave the column blank. I would like to change these NaN values in Table B(1:end,6) from NaN to 'Outside'. The values in this column will be all 'Outside' if the user imports the matrix with this column filled or will leave it blank and I will need to then convert from NaN to 'Outside'. Thank you!