error_reporting —You can turn on & turn OFF errors at the run time.
If you set 0: Turn off all PHP error
// Turn off all error reporting error_reporting(0);
If you set -1:Report all PHP errors
// Report all PHP errors error_reporting(-1);
E_ALL: Turn on all PHP errors
// Turn on all PHP errors error_reporting(E_ALL);
Suggestion: if your site is in production mode(Live) we will suggest to turn off all PHP error reporting for security purpose.