Get category from post in wordpress

$categories = get_the_category();
$separator = ', ';
$output = '';
if($categories){
foreach($categories as $category) {
$output .= '<a href="'.get_category_link( $category->term_id ).'" title="' . esc_attr( sprintf( __( "View all posts in %s" ), $category->name ) ) . '">'.$category->cat_name.'</a>'.$separator;
}
echo trim($output, $separator);
}