Update module ApplicationHelper

app/helpers/application_helper.rb

-# Returns the full title on a per-page basis.       # Documentation comment
-def full_title(page_title = "" )                     # Method def, optional arg
-  base_title = "Ruby on Rails Tutorial Sample App"  # Variable assignment
-  if page_title.empty?                              # Boolean test
-    base_title                                      # Implicit return
-  else
-    page_title + " | " + base_title                 # String concatenation
+module ApplicationHelper
+
+  # Returns the full title on a per-page basis.
+  def full_title(page_title = '')
+    base_title = "Ruby on Rails Tutorial Sample App"
+    if page_title.empty?
+      base_title
+    else
+      page_title + " | " + base_title
+    end
   end
 end
-end