I've got a defined group of seven different publish types and want to display a symbol for every one out of the search engine results list.

I have got the next code to show the publish type but have no clue how you can extend it into an if

<?php $post_type = get_post_type_object( get_post_type($post) );
echo $post_type->label ; ?>

Any help appreciated.

You are able to display different symbols such as this:

<?php 
   $post_type = get_post_type($post);
   switch ($post_type) {
       case "type1":
           echo "<img src='label1.png'/>";
           break;
       case "type2":
           echo "<img src='label2.png'/>";
           break;
   }
?>

Better still, should you incorporated publish type names in icon filenames, you can just place publish enter in the src attrib by img tag:

<img src="post_type_<?= get_post_type($post) ?>.png"/>