How to write mutilple information in text file using windows batch scripting

Question

I have a text file with no. of file formats. I want to print those file names to one text file one by one. Problem here is as soon as it check second file format name and try to write in text file, it will erase the first record info.Here is what I have return

@ECHO OFF
setlocal enableDelayedExpansion
SET "formats=.css.js.jsp."
FOR /F "delims=#" %%A in (demo.txt) do (
   IF "!formats:%%~xA.=!" neq "!formats!" (
     %%~nxA > output.txt
   ) ELSE (
     ECHO Incorrect file format
   )
) 

Answer 1

Just use >> redirection.

%%~nxA >> output.txt

It will append redirected output to the end of your file, instead of cleaning the file before redirecting output there.