Hi,
Thanks !
Well, as I said you can change that in the settings.
However, if you can do it in the view file it's better because the setting will affect the display everywhere, in the cart, the checkout, the backend etc.
If you just want it different on the listings and products pages. It's better to do an override of listing_price.php
The format function is not documented. But you can't do much with it as you need to pass the currency_id and then it displays the price according to the settings of the currency.
I would have also used sprintf in your case.