fork download
copy 
  1. //
  2. //  OverloadOverride - demonstrate when a function is
  3. //                     declare-time overloaded vs. runtime
  4. //                     overridden
  5. //
  6. #include <cstdio>
  7. #include <cstdlib>
  8. #include <iostream>
  9. using namespace std;
  10.  
  11. class Student
  12. {
  13.   public:
  14.     // uncomment one or the other of the next
  15.     // two lines; one binds calcTuition() early and
  16.     // the other late
  17. //          float calcTuition()
  18.     virtual float calcTuition()
  19.     {
  20.         cout << "We're in Student::calcTuition" << endl;
  21.         return 0;
  22.     }
  23. };
  24.  
  25. class GraduateStudent : public Student
  26. {
  27.   public:
  28.     float calcTuition()
  29.     {
  30.         cout << "We're in GraduateStudent::calcTuition" 
  31.              << endl;
  32.         return 0;
  33.     }
  34. };
  35.  
  36. void fn(Student& x)
  37. {
  38.     x.calcTuition();   // to which calcTuition() does 
  39.                      // this refer?
  40. }
  41.  
  42. int main(int nNumberofArgs, char* pszArgs[])
  43. {
  44.     // pass a base class object to function
  45.     // (to match the declaration)
  46.     Student s;
  47.     fn(s);
  48.  
  49.     // pass a specialization of the base class instead
  50.     GraduateStudent gs;
  51.     fn(gs);
  52.     return 0; 
  53. }
  54.  
  55.  
Success #stdin #stdout 0s 3140KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
We're in Student::calcTuition
We're in GraduateStudent::calcTuition
https://ideone.com/Nd8hs9
language:
C++14 (gcc 8.3)
created:
9 years ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!