Initial commit

c++/Others/A simple example using a virtual function..cpp

@@ -0,0 +1,55 @@
+A simple example using a virtual function.
+#include <iostream>
+using namespace std;
+
+class BaseClass {
+public:
+  int i;
+  BaseClass(int x) { 
+     i = x; 
+  }
+  virtual void myFunction()
+  {
+    cout << "Using BaseClass version of myFunction(): ";
+    cout << i << '\n';
+  }
+};
+
+class DerivedClass1 : public BaseClass {
+public:
+  DerivedClass1(int x) : BaseClass(x) {}
+  void myFunction() 
+  {
+    cout << "Using DerivedClass1's version of myFunction(): ";
+    cout << i*i << '\n';
+  }
+};
+
+class DerivedClass2 : public BaseClass {
+public:
+  DerivedClass2(int x) : BaseClass(x) {}
+  void myFunction() 
+  {
+    cout << "Using DerivedClass2's version of myFunction(): ";
+    cout << i+i << '\n';
+  }
+};
+
+int main()
+{
+  BaseClass *p;
+  BaseClass ob(10);  
+  DerivedClass1 derivedObject1(10);   
+  DerivedClass2 derivedObject2(10); 
+
+  p = &ob;
+  p->myFunction();                         // use BaseClass's myFunction()
+
+  p = &derivedObject1;
+  p->myFunction();                         // use DerivedClass1's myFunction()
+
+  p = &derivedObject2;
+  p->myFunction();                         // use DerivedClass2's myFunction()
+
+  return 0;
+}