13年题。

OOP/13Exam/3.2.cpp

@@ -0,0 +1,43 @@
+#include <iostream>
+using namespace std;
+
+class A {
+    public:
+    A() {
+        cout << "A::A() called.\n";
+    }
+    virtual ~A() {
+        cout << "A::~A() called.\n";
+    }
+};
+
+class B: public A {
+    public:
+    B(int i) {
+        cout << "B::B() called.\n";
+        buf = new char[i];
+    }
+    virtual ~B() {
+        delete [] buf;
+        cout << "B::~B() called.\n";
+    }
+
+    private:
+    char *buf;
+};
+
+void fun(A *a) {
+    delete a;
+}
+
+int main() {
+    A *a = new B(15);
+    fun(a);
+}
+
+/*
+A::A() called.
+B::B() called.
+B::~B() called.
+A::~A() called.
+*/