@ Sun Xin C ++ note

@ Just get independent blog: http://blog.forgetwind.com, welcome to step on.

1: The premise of type conversion, memory model matching.
2: C ++ polymorphism:
When the C ++ compiler is compiling, it finds that print of Class A is a virtual function, and C ++ will use
The late binding technology depends on the object type (Program, We
The first address of Class B passed) to determine which function to call. This capability is called C ++ polymorphism.
(Determine-normal, or during compilation, and-virtual during runtime)

 # Include  <  Iostream  >  
  Using     Namespace  STD;

 Class  A {
  Public  :
A (){}
  ~  A (){}
  Virtual     Void  Print (){
Cout  <     "  A  "     < Endl;
}
};

  Class  B:  Public  A {
  Public  :
B (){}
  ~  B (){}
  Virtual     Void  Print (){
Cout  <     " B  "     <  Endl;
}
};

  Int  Main (){
B;
A  *  A  = &  B;
A  ->  Print ();
  //  Late binding to check whether print exists in Class B. If yes, the print of the derived class is called.  
   Return     0  ;
} 

3: Based on the Principle of inheritance, the this pointer in the base class points to the object of the derived class.
(@ Sun Xin C ++ video 3 _ test program, adjustable to view the running process)

 # Include  <  Iostream  >  
  Using     Namespace  STD;

  Class  A;
A *  PT  =  NULL;

  Class  A {
  Public  :
A (){
PT  =     This  ;
}

  Virtual     Void  Print (){
Cout <     "  This pointer of the base class A points to the object of.  "     <  Endl;
}
};

  Class  B:  Public  A {
  Public  :
B (){}
  Virtual     Void Print (){
Cout  <     "  This pointer of the base class A points to the object of B.  "     <  Endl;
}
};
B test;  //  When the base class constructor is called, PT points to this in.  
   
  Int  Main (){
PT  -> Print ();
  Return     0  ;
}