What possibilities are there to debug the controller?

I have a controller creating a big hash of audio files out of several subfolders (2015, 2014 etc) to create a big list of recordings. There is something wrong inside the hash and I have a hard time finding the error. I realised that I can’t use dump() inside the controller. How do you guys debug your controller methods?

What do you mean by hash?

You should be able to use var_dump() and die() in your controller.

What do you mean by hash?

A multi-dimensional array.
Thanks for you reply! var_dump() helped me to debug my problem.