Extracting values from file names to array

Let's say I have a directory "mydirectory" and in it, I have some files

file_234.txt
file_356.txt
file_567.txt
file_987.txt

and I want to form an array in Matlab out of the respective numbers.

234
356
567
987

How can I go into the directory, extract the information from the files, and put each value into the array?

Thanks!

Answer 1

[Stephen23]

>> D = 'path to the folder where the files are saved';
>> S = dir(fullfile(D,'file_*.txt'));

Method one: regexp:

>> V = str2double(regexp({S.name},'\d+','match','once'))
V =
   234   356   567   987

Method two: sscanf:

>> V = sscanf([S.name],'file_%d.txt') % change to suit your filenames
V =
   234
   356
   567
   987

Answer 2

[Sean de Wolski]

fn = ["file_234.txt"
"file_356.txt"
"file_567.txt"
"file_987.txt"]

double(extractBetween(fn, "_", "."))