How do I find output as the path of any input stored in cells?

Suppose I have the main folder 'X' which has a subfolder 'a'. now a is like a linear array with n elements. Now picking any random element out of it, the output should show the path i.e, X\a\n. Like 'a' there would be columnar till z. So it would be like a rectangular matrix. Need urgent help with this

[KL]

Show us an example. How does your X and a look like and how would you expect the output for that particular example. The elements of a are all unique including all elements in X?

[kd p]

[kd p]

let all are unique and not necessarily integer values get stored

[Walter Roberson]

http://www.mathworks.com/matlabcentral/answers/29922-why-your-question-is-not-urgent-or-an-emergency

[Guillaume]

"has a subfolder 'a'. now a is like a linear array with n elements."

Huh? What is like a linear array about a subfolder?

Can you show an example of input and desired output using matlab syntax, as text not as screenshot.

Are you, per chance, looking at listing the content of a folder and all its subfolders?

[kd p]

Pardon me @Walter. Actually, I had a deadline and I'm new here.

[kd p]

It is analogous to a subfolder. I used the word to describe the paths as output. Input would be like I said in the image, the output would be just the path of the element of the desired position.

Answer 1

[Walter Roberson]

projectdir = fullfile('X', 'a');
dinfo = dir( projectdir );
dinfo(ismember({dinfo.name}, {'.', '..'})) = [];   %remove . and ..
numentries = length(dinfo);
random_entry_idx = randi(numentries);
random_entry_filename = dinfo(random_entry_idx).name;
random_name = fullfile(projectdir, random_entry_filename);

[kd p]

Thank You. But it's showing error in line 5

[Walter Roberson]

projectdir = fullfile('X', 'a');
if ~exist(projectdir, 'dir')
  error('Folder "%s" does not exist relative to here', projectdir);
end

dinfo = dir( projectdir );
dinfo(ismember({dinfo.name}, {'.', '..'})) = [];   %remove . and ..
numentries = length(dinfo);
if numentries == 0
  error('Folder "%s" exists but has no files in it', projectdir);
end
random_entry_idx = randi(numentries);
random_entry_filename = dinfo(random_entry_idx).name;
random_name = fullfile(projectdir, random_entry_filename);

[kd p]

Thank You, Walter. Could you kindly say what does the "remove '.' and '..' parts mean? Like I have to edit something in it or totally remove them? And besides, the code is showing error in the output