best practice to use action url while calling ajax in cakePHP

Question

I am using ajax with jQuery in my cakePHP application.
and my javascript function is placed inside a javascript file.

now in my local system the files are kept

Answer 1

@irtiza your answer is appreciated but for cakephp latest version 3.x this will work otherwise you will get routing error.

ulr:' 
'controllername', 'action' => 'actionname')); ?>'