When i started my nodejs express server on port 4000 using nodemon it create a new executable file 4000,
And every time file changes and server started it throw error that address already in use and when i kill that process which are associated with these port then after it is throwing the same error
yarn dev
it create 4000, file automatically at root level of project
again i change port to 5000
yarn dev
again it create file 5000,
After long struggle i have found the error . My .env file was like this:-
PORT=4000, MONGODB_URI=mongodb://localhost:27017/test,
problem arises due added comma(,) after value . After removal of comma problem fixed