详解C++中的析构函数

class String 
{ 
private: 
	char *s; 
	int size; 
public: 
	String(char *); // constructor 
	~String();	 // destructor 
}; 
 
String::String(char *c) 
{ 
	size = strlen(c); 
	s = new char[size+1]; 
	strcpy(s,c); 
} 
 
String::~String() 
{ 
	delete []s; 
} 

#include <iostream> 
using namespace std; 
class Test { 
private: 
	~Test() {} 
}; 
int main() 
{ 
	Test t; 
} 

int main() 
{ 
 Test* t;           
} 

int main() 
{ 
 Test* t = new Test; 
} 

int main() 
{ 
 Test* t = new Test;
 delete t;//编译出错，无法调用私有的析构函数 
}

#include <iostream> 

class Test { 
private: 
	~Test() {} 
	friend void destructTest(Test*); 
}; 

void destructTest(Test* ptr) 
{ 
	delete ptr; 
} 

int main() 
{ 
	Test* ptr = new Test; 
	destructTest(ptr); 

	return 0; 
} 

class Test { 
public:
 destroy(){delete this};
private: 
	~Test() {} 
};

#include <iostream>
using namespace std;
class Base
{
public:
 Base(){
  cout << "Base Constructor Called\n";
 }
 ~Base(){
  cout << "Base Destructor called\n";
 }
};
class Derived1: public Base
{
public:
 Derived1(){
  cout << "Derived constructor called\n";
 }
 ~Derived1(){
  cout << "Derived destructor called\n";
 }
};
int main()
{
 Base *b = new Derived1();
 delete b;
}

class B
{public: virtual ~B(){cout<<"基类B执行了"<<endl; }
};

class D
{public:virtual ~D(){cout<<"成员D执行了"<<endl; }
} ;

class E
{public:virtual ~E(){cout<<"成员E执行了"<<endl; }
} ;

class A
{public:virtual ~A(){cout<<"基类A执行了"<<endl;}; 
};

class C:public A,B
{
 public:virtual ~C(){cout<<"派生类执行了"<<endl;};
 private:
  E e;
  D d;
};

int main() 
{ 
 C *c;
 c=new C();
 delete c;
}