Closes one or more files or devices opened by the OPEN statement.
CLOSE [[ # ]file_number[, [ # ]file_number]]…
file_number is the file number assigned to the file or device in its OPEN statement.
You can specify more than one file number in a single CLOSE statement.
Once you close a file number, you cannot use the file number for read or write operations until you open a new file.
The CLEAR, END, RESET, RUN and SYSTEM statements close your files automatically. For housekeeping purposes, however, you should issue a corresponding CLOSE statement for each OPEN statement in your program.
CLOSE with no arguments closes all open files and devices.
OPEN "TEST.DAT" FOR OUTPUT AS #1
PRINT #1, "This is a test"
CLOSE #1