<?php
/* FIRST
* Note: This function only returns results from the default “category” taxonomy. For custom taxonomies use get_the_terms().
*/
$categories = get_the_terms( $post->ID, 'taxonomy' );
// now you can view your category in array:
// using var_dump( $categories );
// or you can take all with foreach:
foreach( $categories as $category ) {
echo $category->term_id . ', ' . $category->slug . ', ' . $category->name . '<br />';
}