1. After modifying the code in the development environment and refreshing the page, it will take more than ten seconds for the changes to appear. Within ten seconds, the page will still stop at the result before the code modification
(ps: the app has been deleted /cache directory, still invalid) Environment: php5.6, apache2.4 local virtual host

2. Later I triedapp/console server:run
open the web page atlocalhost:8000/app_dev.php, modified the code, and the refresh took effect immediately.

3.question: Why is it useless to delete the cache directory of the virtual host... (Now you can only use this command line to start the program for coding. What will happen if you try to transfer it to the server later)