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/// @file exam_1_1.cpp/// @brief /**1. 完成一个字符串类, 操作变长字符串class CMyString  {private:char* m_lpString;int   m_nLen;int   m_nSpaceLen;};*/#include 
   
    #include 
    
     using namespace std;#include "MyString.h"void fnTestString();void clear_cin();int main(int argc, char** argv, char** envp){    fnTestString();    cout << "END, press any key to quit" << endl;    clear_cin();    getchar();    return 0;}void fnTestString(){    CMyString str1;    CMyString str2;    CMyString str3;    CMyString str4;    CMyString str5;    str1 = CMyString("Hello");    str1.strcpy(" world");    cout << str1.getString() << endl;    str2 = str1;    str2.strcat(" c++");    cout << str2.getString() << endl;    str1.setString("hello c++");    cout << str1.getString() << endl;    str3.strcpy("test strcpy");    cout << str3.getString() << endl;    str4.strcat("test strcat");    cout << str4.getString() << endl;    cout << str5.getString() << endl;}void clear_cin(){    cin.clear();    cin.sync();}
    
   

// MyString.h: interface for the CMyString class.////#if !defined(AFX_MYSTRING_H__F5118BD7_4C05_47F1_AD8E_D18B1F44B0CA__INCLUDED_)#define AFX_MYSTRING_H__F5118BD7_4C05_47F1_AD8E_D18B1F44B0CA__INCLUDED_#if _MSC_VER > 1000#pragma once#endif // _MSC_VER > 1000#ifndef NULL#define NULL 0#endif#ifndef SAFE_DELETE    #define SAFE_DELETE(x) \    { \        if (NULL != (x)) \        { \        delete (x); \        (x) = NULL; \        } \    }#endif // #ifndef SAFE_DELETE#ifndef SAFE_DELETE_ARY    #define SAFE_DELETE_ARY(x) \    { \        if (NULL != (x)) \        { \        delete[] (x); \        (x) = NULL; \        } \    }#endif // #ifndef SAFE_DELETE_ARYclass CMyString  {public:	CMyString();	virtual ~CMyString();    // copy construct function    CMyString(CMyString& src);    CMyString(CMyString* psrc);    CMyString(const char* psrc);    CMyString& operator = (const CMyString& src);    // member method    void setString(const char* pSrc);    const char* getString() const;    void strcpy(const char* pSrc);    void strcat(const char* pSrc);private:    void init();    void uninit();    // member dataprivate:    char* m_lpString; ///< 开辟(new)的字符串缓冲区    int   m_nLen; ///< 字符串长度    /// 如果最终要操作的字符串比缓冲区小, 就不用另外再开辟缓冲区了    int   m_nSpaceLen; ///< 缓冲区总长度};#endif // !defined(AFX_MYSTRING_H__F5118BD7_4C05_47F1_AD8E_D18B1F44B0CA__INCLUDED_)

// MyString.cpp: implementation of the CMyString class.////#include 
   
    #include 
    
     #include "MyString.h"//// Construction/Destruction//CMyString::CMyString(){    init();}CMyString::CMyString(CMyString& src){    init();    this->strcpy(src.getString());}CMyString::CMyString(CMyString* psrc){    init();    if (NULL != psrc)    {        this->strcpy(psrc->getString());    }}CMyString::CMyString(const char* psrc){    init();    this->strcpy(psrc);}CMyString& CMyString::operator = (const CMyString& src){    this->strcpy(src.getString());    return *this;}void CMyString::setString(const char* pSrc){    this->strcpy(pSrc);}const char* CMyString::getString() const{    if (NULL == m_lpString)    {        return "";    }    else    {        return m_lpString;    }}void CMyString::strcpy(const char* pSrc){    int iLenNew = 0;    char* pNewString = NULL;    if (NULL == pSrc)    {        return;    }        iLenNew = ::strlen(pSrc);    if (iLenNew > (m_nSpaceLen - 1))    {        pNewString = new char[iLenNew + 1];        _ASSERT(NULL != pNewString);        pNewString[0] = '\0';        ::strcpy(pNewString, pSrc);        SAFE_DELETE_ARY(m_lpString);                m_nLen = iLenNew;        m_nSpaceLen = m_nLen + 1;        m_lpString = pNewString;    }    else    {        m_nLen = strlen(pSrc);        _ASSERT(NULL != m_lpString);        ::strcpy(m_lpString, pSrc);    }}void CMyString::strcat(const char* pSrc){    int iLenNew = 0;    char* pNewString = NULL;    if (NULL == pSrc)    {        return;    }    if (NULL == m_lpString)    {        this->strcpy(pSrc);        return;    }    iLenNew = m_nLen + strlen(pSrc);    if (iLenNew > (m_nSpaceLen - 1))    {        pNewString = new char[iLenNew + 1];        pNewString[0] = '\0';        ::strcpy(pNewString, m_lpString);        SAFE_DELETE_ARY(m_lpString);        ::strcat(pNewString, pSrc);        m_nLen = iLenNew;        m_nSpaceLen = m_nLen + 1;        m_lpString = pNewString;    }    else    {        m_nLen += strlen(pSrc);        ::strcat(m_lpString, pSrc);    }}CMyString::~CMyString(){    uninit();}void CMyString::init(){    m_lpString = NULL;    m_nLen = 0;    m_nSpaceLen = 0;}void CMyString::uninit(){    if (NULL != m_lpString)    {        SAFE_DELETE_ARY(m_lpString);    }}
    
   

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