MATLAB: Save figures in a subfolder after 2 for loops

Question

I have created 2 for loop. The first is for 5 subjects. The second one is for 4 measurements. Then I have a code to save a figure for each subject per test. But now it stores each figure in my main folder 'Data_examen'. I want to create a subfolder for each subject, so 'Subject1'…'Subject5'. And each subfolder must contain the 4 figures of their measurements… I have no idea how to do this. But this is my code I already have:

for welke_pp=1:aantal_pp %for 5 subjects
  ...
    end
for i_testen=1:length(data_stair_rise)-1 %for 4 measurements
folder = 'Data_examen' %my main folder (where I want to create my subfolders...)
  
% Create a PNG filename.
 pngFileName = sprintf('3Dplot_subject%d_trial%d.png', welke_pp, i_testen);
 fullFileName = fullfile(folder, pngFileName);
saveas(gcf,fullFileName); %save current opened figure

Answer 1

use mkdir to create a folder and change the folder name you save on to the relevant folder.

and you can use cd, dir and other command to see or move to other folders.