$scope.menuState变量未初始化

Author: iroben

Chapter2.markdown

@@ -499,7 +499,9 @@
 ```
 ```js
     function DeathrayMenuController($scope){
-        $scope.menuState.show = false;
+        $scope.menuState = {
+        	show: false
+        };
 
         $scope.toggleMenu = function(){
             $scope.menuState.show = !$scope.menuState.show;