Override/override of member variables inherited in C ++

First, you need to understand:

(1) Coverage of member functions: the Child class must overwrite the member functions of the parent class. The function names, parameters, and return values must be consistent (of course, the compiler determines );

(2) Coverage of member variables: the Child class only covers the inherited member variables and does not change the variables in the original parent class;

(3) constructor starts from the base class. variables of the same name of each class are not overwritten and are independent variables. Subclass calls the proximity principle. If the parent class has an interface, it will give priority to calls. If the parent class does not exist, it will call the grandfather class interface. Of course, if you have a parent class, it will first call its own function;

Let's first look at a program:

# Include "stdafx. H "# include <iostream >#include <string> using namespace STD; Class A {public: int m; A () {M = 1; printf (". M = % d \ n ", this-> m);} void print () {printf (" % d \ n ", this-> m );}}; class B: Public A {public: int m; B () {m = 2; printf ("B. M = % d \ n ", this-> m) ;}}; int _ tmain (INT argc, _ tchar * argv []) {B; B. print (); printf ("% d \ n", B. m); Return 0 ;} /// ==================================================== output a. M = 1b. M = 212

 

That is to say, during the call process, the program first constructs a base class, sets m in a to 1, then constructs a subclass, sets m in B to 2, and then calls B. print (); in this case, the m values in A and B are 1 and 2. B searches for the print function in Class B and finds that the function does not exist, and then searches for the function in its parent class, output B. m, so is m a member function in Class A or Class B? Of course, it is a member variable in Class A. Why?

Let's see what C ++ primer says?