p.132-p.133 extract method "calculate_outstanding"

chapter6/Extract_Method.rb

@@ -17,15 +17,8 @@ def order_entry(amount)
   end
 
   def print_owing
-    outstanding = 0.0
-
     print_banner
-
-    #勘定を計算(calculate outstanding)
-    @orders.each do |order|
-      outstanding += order.amount
-    end
-
+    outstanding = calculate_outstanding
     print_details outstanding
   end
 
@@ -43,3 +36,11 @@ def print_details(outstanding)
   puts "name: #{@name}"
   puts "amount: #{outstanding}"
 end
+
+def calculate_outstanding
+  outstanding = 0.0
+  @orders.each do |order|
+    outstanding += order.amount
+  end
+  outstanding
+end