PHP Array第一个变量无法识别

I am creating an extension of an existing Visual Composer Plugin. And everything works fine but one variable is not recognized. And I can't figure out why.

 if($vor_icon_style == "bg-sprechblase" ||
   $vor_icon_style == "bg-konfigurator" ||
   $vor_icon_style == "bg-koffer" ||
   $vor_icon_style == "bg-stoppuhr" ||
   $vor_icon_style == "bg-prozente" ||
   $vor_icon_style == "bg-maus"
  )
$end_content .= '<figcaption>
                        <div>
                            <h2 style="color:'.$title_overlay_font_color.';font-size:'.$title_font_size.';">'.$header.' <span>'.$header2.'</span></h2>
                            <p style="color:'.$description_font_color.';font-size:'.$description_font_size.';">'.$content.'</p>
                        </div>
                        <a class="service websites" href="'.$href['url'].'" title="'.$href['title'].'"></a>
                    </figcaption>';
$end_content .= '</figure></div>';

return $end_content;

And in Visual Composer I have created this map:

vc_map( array(
"base" => "vc_doo_voreingestelle_icons",
"name" => __( "Voreingestellte Icons", "doo-text-domain" ),
"icon" => "dt_vc_fashion_banner",
'admin_enqueue_css' => array(get_template_directory_uri().'/vc_doo_banner.css'),
'category' => __( 'Doo', "doo-text-domain" ),
'description' => __( 'Voreingestellte Icons', "doo-text-domain" ),
"params" => array(
    array(
      "type"        => "dropdown",
      "heading"     => __("Welches Icon soll angezeigt werden?", "doo-text-domain"),
      "param_name"  => "vor_icon_style",
      "value"       => array(
        'Sprechblase' => 'bg-sprechblase',
        'Konfigurator' => 'bg-konfigurator',
        'Koffer' => 'bg-koffer',
        'Stoppuhr'  => 'bg-stoppuhr',
        'Prozente'  => 'bg-prozente',
        'Maus'  => 'bg-maus',
      ),
      "description" => __("Bitte das Icon auswählen")
    ),

[...]

And all Vor_Icon_styles can be selected and extend the class. But not "BG-SPRECHBLASE".

Does anyone have an idea?

Greez and thank you!

Ok, so it appears that the first variable in an array in visual composer is a placeholder variable.

So I added a description into the array as the first element:

vc_map( array(
"base" => "vc_doo_voreingestelle_icons",
"name" => __( "Voreingestellte Icons", "doo-text-domain" ),
"icon" => "dt_vc_fashion_banner",
'admin_enqueue_css' => array(get_template_directory_uri().'/vc_doo_banner.css'),
'category' => __( 'Doo', "doo-text-domain" ),
'description' => __( 'Voreingestellte Icons', "doo-text-domain" ),
"params" => array(
    array(
      "type"        => "dropdown",
      "heading"     => __("Welches Icon soll angezeigt werden?", "doo-text-domain"),
      "param_name"  => "vor_icon_style",
      "value"       => array(
        'Bitte auswählen' => 'bg-sprechblase', //PLACEHOLDER VARIABLE
        'Sprechblase' => 'bg-sprechblase',
        'Konfigurator' => 'bg-konfigurator',
        'Koffer' => 'bg-koffer',
        'Stoppuhr'  => 'bg-stoppuhr',
        'Prozente'  => 'bg-prozente',
        'Maus'  => 'bg-maus',
      ),
      "description" => __("Bitte das Icon auswählen")
    ),

That works.