[Wordpress] Array echo value

[Julson]

Hi,

I'm customizing a wordpress-theme and I'm trying to echo a value from an array (with several names of categories).
My problem: I can't figure out how to echo the specific value (= the name of the category) rather than the word "Array".

The wordpress-functions is_category() and in_category() are able to handle arrays, but the echo just prints "Array".

Could you help me? 🙂 Thanks!

function cat_background_image (){

$category_class = array('wissen', 'meinung', 'wirtschaft'); //category_names

if (is_single()) {

if(in_category($category_class))  echo  'class="bg_' .$category_class. '" ';

} else {

if(is_category($category_class))  echo  'class="bg_' .$category_class. '" ';

}
}

[bradgrafelman]

Well.. which value in $category_class do you want to use in those echo statements?

[Julson]

Hmm, the thing is: it should not always be the same, so I can't add an ID... it should be the value of the category that is currently opened. is_category() and in_category() do that correctly, they react only on the three categories in the array.
Thanks!