学步园

// StringClass.cpp : 定义控制台应用程序的入口点。
//

#include "stdafx.h"
#include "iostream"
#include "string"
using namespace std;

class CMyString
{
public:
	CMyString(char * pData = "denggaoxiang");
	CMyString(const CMyString& str);
	CMyString& CMyString::operator = (const CMyString & str);
	~CMyString();
private:
	char * m_ptr;
};
CMyString::CMyString(char *pData)
{
	int len = strlen (pData);
	if (pData == NULL)
	{
		if ((m_ptr = new char[1]) != NULL)
		{
			*m_ptr = '\0';
		}
	}
	else if ((m_ptr = new char [len+1]) != 0)
	{
		for (int i = 0; i < len ; i ++)
			*(m_ptr+i) = *(pData+i);
		*(m_ptr+len) = '\0';
	}
}
CMyString::CMyString(const CMyString& str)
{
	int len = strlen(str.m_ptr);
	if ((m_ptr = new char[len + 1]) != NULL)
	{
		for (int i = 0; i < len; i ++)
		{
			*(m_ptr+i) = *(str.m_ptr+i);
		}
		*(m_ptr + len) = '\0';
	}
}
CMyString& CMyString::operator = (const CMyString& str)
{
	if (this == &str)
		return *this;
	delete [] m_ptr;
	m_ptr = NULL;
	int len = strlen(str.m_ptr);
	if ((m_ptr = new char [len + 1]) != 0)
	{
		for (int i = 0; i < len; i ++)
		{
			*(m_ptr+i) = *(str.m_ptr+i);
		}
		*(m_ptr + len) = '\0';
	}
	return *this;
}

CMyString::~CMyString()
{
	if (m_ptr != NULL)
	{
		delete[] m_ptr;
		m_ptr = NULL;
	}
}


int _tmain(int argc, _TCHAR* argv[])
{
	CMyString str("gao");
	CMyString str1 = str;
	CMyString str2 = str1 = str1;
	

}