CodePudding user response:

 
1: vc, class A, B, C; This statement is wrong, only the class A; Class B; Class c. 
2: the Dog has no constructor, Person& The owner; Are not enough, must Person * owner; 
3: if the Person, legs, Ring, is a statement, then legs legs [4]. Is wrong; Must be defined first, to use structure content 
4: Dog Pattern; Is wrong, can not tolerate, 
5: the static char c='a'; Can't, must be static const char c='a';