Initial commit

c++/Others/Abstract base class.cpp

@@ -0,0 +1,36 @@
+Abstract base class
+#include <iostream>
+using namespace std;
+
+class CPolygon {
+  protected:
+    int width, height;
+  public:
+    void set_values (int a, int b)
+      { width=a; height=b; }
+    virtual int area (void) =0;
+};
+
+class CRectangle: public CPolygon {
+  public:
+    int area (void)
+      { return (width * height); }
+};
+
+class CTriangle: public CPolygon {
+  public:
+    int area (void)
+      { return (width * height / 2); }
+};
+
+int main () {
+  CRectangle rect;
+  CTriangle trgl;
+  CPolygon * ppoly1 = ▭
+  CPolygon * ppoly2 = &trgl;
+  ppoly1->set_values (4,5);
+  ppoly2->set_values (4,5);
+  cout << ppoly1->area() << endl;
+  cout << ppoly2->area() << endl;
+  return 0;
+}