$category_slug_array = array(\'slug_1\', \'slug_2\', \'slug_2\'); //array of category slugs

foreach($category_slug_array as $category_slug){
   $my_categories[] = get_term_by( \'slug\', $category_slug, \'category\'); //getting category object by slug
}

print_r($my_categories); //printing array of categories