diff --git a/ch1_firstCase/ch1_switch/movie.cpp b/ch1_firstCase/ch1_switch/movie.cpp
index 196cffc..82d3e43 100644
--- a/ch1_firstCase/ch1_switch/movie.cpp
+++ b/ch1_firstCase/ch1_switch/movie.cpp
@@ -21,3 +21,25 @@ std::__cxx11::string Movie::getTitle()
     return _title;
 }
 
+double Movie::getCharge(int daysRented)
+{
+    double result = 0;
+    switch(getPriceCode()) {
+    case Movie::REGULAR:             //普通片，起步价为2元，租期超过2天的部分每天1.5元
+        result += 2;
+        if(daysRented > 2)
+            result += (daysRented - 2) * 1.5;
+        break;
+    case Movie::NEW_RELEASE:             //新片，每天3元
+        result += daysRented * 3;
+        break;
+    case Movie::CHILDRENS:             //儿童片，起步价1.5元，租期超过3天的部分每天1.5元
+        result += 1.5;
+        if(daysRented > 3)
+            result += (daysRented - 3) * 1.5;
+        break;
+    }
+
+    return result;
+}
+
diff --git a/ch1_firstCase/ch1_switch/movie.h b/ch1_firstCase/ch1_switch/movie.h
index a50d113..0dfa8d6 100644
--- a/ch1_firstCase/ch1_switch/movie.h
+++ b/ch1_firstCase/ch1_switch/movie.h
@@ -7,17 +7,19 @@
 class Movie
 {
 public:
+    enum category {
+        REGULAR = 0,            //普通影片
+        NEW_RELEASE,            //新片
+        CHILDRENS               //儿童影片
+    };
+
     Movie(std::string title = "empty", int price = 0);
 
     int getPriceCode();
     void setPriceCode(int arg);
     std::string getTitle();
+    double getCharge(int daysRented);
 
-    enum category {
-        REGULAR = 0,            //普通影片
-        NEW_RELEASE,            //新片
-        CHILDRENS               //儿童影片
-    };
 
 private:
     std::string _title;                 //影片名
diff --git a/ch1_firstCase/ch1_switch/rental.cpp b/ch1_firstCase/ch1_switch/rental.cpp
index 1f3a48b..162deba 100644
--- a/ch1_firstCase/ch1_switch/rental.cpp
+++ b/ch1_firstCase/ch1_switch/rental.cpp
@@ -18,24 +18,7 @@ Movie Rental::getMovie()
 
 double Rental::getCharge()
 {
-    double result = 0;
-    switch(getMovie().getPriceCode()) {
-    case Movie::REGULAR:             //普通片，起步价为2元，租期超过2天的部分每天1.5元
-        result += 2;
-        if(getDaysRented() > 2)
-            result += (getDaysRented() - 2) * 1.5;
-        break;
-    case Movie::NEW_RELEASE:             //新片，每天3元
-        result += getDaysRented() * 3;
-        break;
-    case Movie::CHILDRENS:             //儿童片，起步价1.5元，租期超过3天的部分每天1.5元
-        result += 1.5;
-        if(getDaysRented() > 3)
-            result += (getDaysRented() - 3) * 1.5;
-        break;
-    }
-
-    return result;
+    return getMovie().getCharge(_daysRented);
 }
 
 int Rental::getFrequentRenterPoints()