number of products per row on category view

hi guys how do i amend the number of products shown per row to 5 from the default 3

I tried to add
// Change number or products per row to 5
add_filter(‘loop_shop_columns’, ‘loop_columns’);
if (!function_exists(‘loop_columns’)) {
function loop_columns() {
return 5; // 5 products per row
}
}

to theme functions but this had no effect