Adding in a function into functions.php but nothing happens, help?

Hey guys!

I’m working on my site and am using Woocommerce for the shop.

I want to display 8 items per page in the shop and looked up some advice from the net.

They said to add

add_filter(‘loop_shop_columns’, ‘loop_columns’);
if (!function_exists(‘loop_columns’))
{
function loop_columns()
{
return 4; // 4 products per row
}
}

and

add_filter( ‘loop_shop_per_page’, create_function( ‘$cols’, ‘return 8;’ ) );

into the functions.php, however when I do that nothing happens, I try adding them at the start or at the end of the php but nothing happens, any idea why?