Variables to TXT file

I have variables in a MAT file that I would like to save the names of and put in a TXT file. Is there a way that I can do this programmatically? 

Answer 1

[MathWorks Support Team]

You may achieve this using "fprintf", as shown in the following code snippet:

clear
%Load MAT File
S = whos();
C = {S.name};
fid = fopen('variable_names.txt','wt');
fprintf(fid,'%s\n',C{:});
fclose(fid);

You may find more information on "fprintf" in the documentation at the following link:

https://www.mathworks.com/help/matlab/ref/fprintf.html

[Stephen23]

This is unusually inefficient code coming from TMW. For example, why call whos twice?:

numvars = length(whos);
w = whos;

when surely once is enough:

w = whos;
numvars = numel(w);

Although constructing the cell array using preallocation of a cell array is not required anyway, because a comma-separated list is much simpler and requires only one line (and so numvars is not required):

   X = {w.name};

versus the code in the answer:

X=cell(1,numvars);
[X{:}]=w.name;

Using fprintf in a loop? Ouch! Much easier to use a comma-separated list again, no loop is required:

fprintf(fid,'%s\n',X{:})

So finally my take on this would be just five simple lines:

S = whos();
C = {S.name};
fid = fopen('variable_names.txt','wt');
fprintf(fid,'%s\n',C{:});
fclose(fid);