Why fileID change every time I run the function?

I'm still a newbie to matlab. It occurs to me every time I run my function,fid changes. Does it matter that fid change?

I used fid = fopen('filename','rt') in paricular.

THis should appear very stupid to you all but I really have nobody to turn to. Thank you!

Answer 1

[Star Strider]

You need to use the fclose function after you have finished reading the file. That closes the file and resets the fileID.

Answer 2

[Steven Lord]

The only specific value for the file ID that matters is -1. That means fopen encountered a problem trying to open the file.

Otherwise, you shouldn't depend on the specific value of the file ID, you should just use the output argument variable from a call to fopen with the other file I/O functions that accept file IDs.