Insert functions-defined constant into get_tags code

Question

I'm using the below code from WordPress' get_tags Function Reference page

    $tags = get_tags();
    $html = '<div class="post_tags">';
    foreach ($tags as $tag){
          $tag_link = get_tag_link($tag->term_id);      
          $html .= "<a href='{$tag_link}' title='{$tag->name} Tag' class='{$tag->slug}'>";
          $html .= "{$tag->name}</a>";}
    $html .= '</div>';
    echo $html;

In my functions.php file I have a number of defined constants.

 define('xyz_city','New York');

I need to insert a constant into the tag link title (line 5 of above code). So instead of .....

    title='{$tag->name} Tag'

it needs to be .....

    title='{$tag->name} [insert xyz_city]'

But it's proving beyond my ability. Normally I echo the constants in like this

    <?php echo xyz_city ;?>

Answer 1

I think this is what you are going for:

$html .= "<a href='{$tag_link}' title='{$tag->name} {$xyz_city}' class='{$tag->slug}'>";

The {$tag->name} part is a way to insert a function or variable into a "double quoted" string definition. In the case of {$tag->name} it needs the {curly braces} to get the whole object->method thing to work. You can usually leave the curly braces out when you have a double quoted string and want to insert a variable like $xyx_city, but its good practice to put them in there anyway just in case the underscore or something else in the name messes up the string parsing.