Default columns per row

Can someone confirm if this is the code in modules/product_listing.php that determines the default number of columns per row using the grid layout?

if (!defined('PRODUCT_LISTING_COLUMNS_PER_ROW')) define('PRODUCT_LISTING_COLUMNS_PER_ROW',3);

I've played around with leaving the number in Admin blank and changing the 3 above for 2 but makes no difference - still shows three columns so just wondering is there something I'm not understanding?

I dont know really but you can configurate in the admin

go to

Configuration->Index Listing->New Products Columns per Row
or
Configuration->Index Listing->Featured Products Columns per Row
or
Configuration->Index Listing->Special Products Columns per Row

whish you cant change

if your using the grid layout module it should have had sql installs to edit the columns per row for the product listing pages.

but to confirm your answer yes that appears to be correct. that line basically says

if PRODUCT_LISTING_COLUMNS_PER_ROW is not defined then define PRODUCT_LISTING_COLUMNS_PER_ROW as 3.