VC 中字串比較和查詢

常用字串函式   
1. 字串比較函式   

    //比較兩個字串是否相同   
    int StrCmp(LPCTSTR lpStr1,LPCTSTR lpStr2);   
    int StrCmpN(LPCTSTR lpStr1,LPCTSTR lpStr2,int nChar);   
    int strcmp( const char *string1, const char *string2 );   
    int wcscmp( const wchar_t *string1, const wchar_t *string2 );   
    int CompareString(LCID Locale, DWORD dwCmpFlags, LPCTSTR lpString1, int cchCount1, LPCTSTR lpString2, int cchCount2);   

2. 計算字串長度   

        HRESULT StringCchLength( LPCTSTR psz,size_t cchMax,size_t *pcch); //replacement for strlen   
          size_t strlen( const char *string );   
          size_t wcslen( const wchar_t *string );   

3. 字串賦值函式   

        HRESULT StringCchCopy(LPTSTR pszDest,size_t cchDest,LPCTSTR pszSrc); //replacement for strcpy   
        HRESULT StringCchCopyN(LPTSTR pszDest,size_t cchDest,LPCTSTR pszSrc,size_t cchSrc); //replacement for strncpy   
        LPTSTR StrCpy(LPTSTR psz1,LPCTSTR psz2); //存在安全問題   
          LPTSTR StrCpyN(LPTSTR psz1,LPCTSTR psz2,int cchMax); //存在安全問題   
          char *strcpy( char *strDestination, const char *strSource );   
          wchar_t *wcscpy( wchar_t *strDestination, const wchar_t *strSource );   
          char *strncpy( char *strDest, const char *strSource, size_t count );   
          wchar_t *wcsncpy( wchar_t*strDest, const wchar_t *strSource, size_t count );   

4. 字串連線函式   

      HRESULT StringCchCat( LPTSTR pszDest,size_t cchDest,LPCTSTR pszSrc); //replacement for strcat   
        HRESULT StringCchCatN( LPTSTR pszDest,size_t cchDest,LPCTSTR pszSrc,size_t cchMaxAppend); //replacement for strncat   
      LPTSTR StrCat( LPTSTR psz1,LPCTSTR psz2); //存在安全問題   
        LPTSTR StrNCat( LPTSTR pszFront,LPCTSTR pszBack,int cchMax); //存在安全問題   
      char *strcat( char *strDestination, const char *strSource );   
        wchar_t *wcscat( wchar_t *strDestination, const wchar_t *strSource );   
        char *strncat( char *strDest, const char *strSource, size_t count );   
        wchar_t *wcsncat( wchar_t *strDest, const wchar_t *strSource, size_t count );   

5. 字元查詢函式   

        //查詢字串中指定字元第一次出現的位置   
        LPTSTR StrChr( LPCTSTR lpStart,TCHAR wMatch); //區分大小寫   
        char *strchr( const char *string, int c );   
        wchar_t *wcschr( const wchar_t *string, wchar_t c );   
        LPTSTR StrChrI( LPCTSTR lpStart,TCHAR wMatch); //不區分大小寫   

      //查詢字串中指定字元最後一次出現的位置   
      LPTSTR StrRChr( LPCTSTR lpStart,LPCTSTR lpEnd,TCHAR wMatch); //區分大小寫   
      char *strrchr( const char*string, int c );   
        wchar *wcsrchr( const wchar_t *string, int c );   
        LPTSTR StrRChrI( LPCTSTR lpStart,LPCTSTR lpEnd,TCHAR wMatch); //不區分大小寫   
        
      *注 StrRChr()函式可以通過StrChr()函式和while迴圈來實現。   

補充：   
查詢字串：   

    _tcsstr（........）   

字串轉化為double型數字   

    _tcstod( const char *nptr, char **endptr )   



字串轉化為double型整數（只取整數部分，不取小數）Convert strings to a long-integer value.   

    _tcstoul ( const char *nptr, char **endptr, int base )   

    _tcstol ( const char *nptr, char **endptr, int base )   



取子字串   

Extracts a substring of length nCount characters from this CStringT object, starting at position iFirst (zero-based).   

CStringT Mid(   
int iFirst,   
int nCount   
) const;   
CStringT Mid(   
int iFirst   
) const;   

example：   

//typedef CStringT < TCHAR, StrTraitATL < TCHAR > > CAtlString;   

CAtlString s( _T("abcdef") );   
_ASSERT( s.Mid( 2, 3 ) == _T("cde") );