the_category if/else statement

Hello 🙂

Please can anyone help me with this?

I’m new in WordPress.

I need to make this: the sence if I have a class dportfolio – show
a category ‘dportfolio’. Otherwise show usual category.

I use:

<?php if ( class_exists( 'DPortfolio' ) ) {
      echo DPortfolio::instance()->dportfolio_get_category();
}; ?>

and when I try to add a second part of a code:
<?php the_category(', ') ?>
with if/else statement, I receive a php error.

Please can someone help me to write this function in a correct way?