A virtual function : virtual function « Class « C++ Tutorial

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C++ Tutorial » Class » virtual function 
9.28.1.A virtual function
#include <iostream> 
using namespace std; 
 
class BaseClass 
public
  virtual void who() { // specify a virtual function 
    cout << "Base\n"
  
}
 
class DerivedClass1 : public BaseClass 
public
  void who() { // redefine who() for DerivedClass1  
    cout << "First derivation\n"
  
}
 
class DerivedClass2 : public BaseClass 
public
  void who() { // redefine who() for DerivedClass2 
    cout << "Second derivation\n"
  
}
 
int main() 

  BaseClass base_obj; 
  BaseClass *p; 
  DerivedClass1 DerivedClass1_obj; 
  DerivedClass2 DerivedClass2_obj; 
 
  p = &base_obj; 
  p->who();  // access BaseClass's who 
 
  p = &DerivedClass1_obj; 
  p->who()// access DerivedClass1's who 
 
  p = &DerivedClass2_obj; 
  p->who();  // access DerivedClass2's who 
   
  return 0
}
Base
First derivation
Second derivation
9.28.virtual function
9.28.1.A virtual function
9.28.2.Access base class's virtual if derived class does not redefine it
9.28.3.Use virtual functions and polymorphism
9.28.4.A pure virtual function
9.28.5.Multiple virtual member functions called in turn
9.28.6.Class with only virtual methods
9.28.7.Use virtual function to calculate area for different shapes
9.28.8.Use Virtual Functions to change the method behaviour
9.28.9.Why Virtual Functions: one interface, multiple methods
9.28.10.Implementing pure virtual functions
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