How do I turn off PHP Notices?

You can disable notices by setting error reporting level to E_ALL & ~E_NOTICE; using either error_reporting ini setting or the error_reporting() function.

However, notices are annoying (I can partly sympathize) but they serve a purpose. You shouldn't be defining a constant twice, the second time won't work and the constant will remain unchanged!

Used This Line In Your Code

error_reporting(E_ALL ^ E_NOTICE);  

I think its helf full to you.

For the command line php, set

error_reporting = E_ALL & ~E_NOTICE

in /etc/php5/cli/php.ini

command php execution then ommits the notices.