// The strongly typed collection class.
 class Names extends LJCCollectionBase
 {
   // Adds a string.
   // This method makes a string collection strongly typed.
   public function Add(string $text)
   {
     $retItem = $this->AddItem($text);
     return $retItem;
   }
 }
 
 // Indicates if a key already exists.
 private static function HasKey()
 {
   $names = new Names();
   $names->Add("First");
   $names->Add("Second");
   $names->Add("Third");
   $value = $names->HasKey(0);
   $result = $value ? "true" : "false";
 
   // result:
   // true;
 }