Turning error reporting off PHP error_reporting() Function

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.