vault backup: 2022-06-21 16:25:48

Affected files:
02. PARA/03. Resources（資源）/Design Pattern.md

02. PARA/03. Resources（資源）/Design Pattern.md

@@ -151,27 +151,46 @@ notify()則是當發生變化時，用來通知所有觀察者的實作。
 假設這樣寫：
 - !!!col
     - 1
-        
+        ### Ingredient class
+        ```cpp
+        class IngredientBubble { ... };
+        class IngredientRedbean { ... };
+        class IngredientGreenbean { ... };
+        class IngredientFairyGrass { ... };
+        ```
 
-````col
-    
+    - 2
+        ### Beverage class
+        ```cpp
+        class BeverageMilkTea { ... };
+        class BeverageGreenTea { ... };
+        class BeverageBlackTea {
+            IngredientBubble* bubble;
+            IngredientRedbean* redbean;
+            IngredientGreenbean* greenbean;
+            IngredientFairyGrass* fairyGrass;
+        }
+        ```
+
+每個飲料的class裡面都將每個配料定義為一個member，如果客人有加配料的話，我們就將配料實例化，假設奶茶加了珍珠：
 ```cpp
-Ingredients
-class BeverageMilkTea { ... };
-class BeverageGreenTea { ... };
 class BeverageBlackTea {
-    
-}
+    void addBubble() {
+        if (!bubble) bubble = new IngredientBubble();
+    }
+};
 ```
 
-
+要算價格的時候：
 ```cpp
-class BeverageMilkTea { ... };
-class BeverageGreenTea { ... };
 class BeverageBlackTea {
-    
-}
-```
-
-````
-
+    void cost() {
+        if (bubble) cost += 10;
+        if (redbean) cost += 10;
+        if (greenbean) cost += 10;
+        if (fairyGrass) cost += 10;
+    }
+private:
+    int32_t cost = 30;  // 奶茶本身10元
+};
+```