Question

I have 50 controllers, and 90 Models. Everywhere i was using/repeating same words ‘login’ and ‘success’. I want to make one global constant so that i can access from anywhere in my controllers and models. How or where do you declare this following 2 line.

Try to put this somewhere to have global access:

defined('MYFIXED_WORD_SUCCESS')
    || define('MYFIXED_WORD_SUCCESS', "success");
defined('MYFIXED_WORD_LOGIN')
    || define('MYFIXED_WORD_SUCCESS', "login");

Example of repeating:

if (count($result) > 0) 
{
  $return = array(
        'flag'  => 'login',  // replace it with MYFIXED_WORD_
        'result'=> 'success',// replace it with MYFIXED_WORD_
        'extra' => array(group'=>$rec->group,));

Answer 1

Anything you include or set in bootstrap.php should be available from anywhere in your application. But have a look at Zend_Translate since it does pretty much what you want but in a organised way.
Alternatively you could set it in application.ini and get to it thru Zend_Config.

You “could” put it in /public/index.php but in my opinion its not the place to put such thing. Imagine when you have thousands of const like that how it would polute a file that basically never should change.