Php code for displaying portfolio category name in portfolio detail page?

Tried the following:

<?php the_category();?>

<?php $categories = get_the_category();foreach ( $categories as $category ) {echo $category;}?>

<?php
$category = implode(" ", get_the_terms( get_the_ID(), 'portfolio_entries' ) );
echo $category;
?>

<?php foreach((get_the_category()) as $category) { echo $category->cat_name . ' '; } ?>

<?php echo esc_html( $sub_category;?>