C++构造函数并不将指针变量初始化为NULL，应该引起足够的注意

// mysqlTest.cpp : 定义控制台应用程序的入口点。
//

#include "stdafx.h"
#include <MRDBIO.h>
#include <DBIO.h>
#include <iostream>
#include <string>
#include <cctype>
#include <cassert>

using namespace std;

class Person
{

public:
Person(string name){this->m_name = name;}
void Display(){cout << "Person Display" << m_name << endl;}
private:
string m_name;
};

class Test
{

public:
Test();

void DisplayIn();
private:
Person *person;
};

Test::Test()
{
if (NULL == person) //注意这行，person初始化的时候并不会为NULL
{
person = new Person("GANQUANFU");//故这语句根本就不会执行,这样的写法存在隐患

}

}

void Test::DisplayIn()
{
person->Display();
}

int _tmain(int argc, _TCHAR* argv[])
{
Test test;
test.DisplayIn();

int wait;
cin >> wait;
return 0;
}