请教scanf_s("%S", ws, 10)和scanf_s("%S", ws[10]);的区别？

码拜

10年 ago

请各位高手解答scanf_s(“%S”, ws, 10)和scanf_s(“%S”, ws[10]);的区别，原来一直以为两个没什么区别，但是今天写书上的习题的时候用scanf_s(“%S”, ws[10])则程序会出故障，然后说让调试程序。如果用scanf_s(“%S”, ws, 10)代替则程序正常完成。请高手解答一下！
10分	本质区别在于： ws和ws[10]的区别：ws是char*，ws[10]是char，scanf需要传入地址，所以正确的是ws scanf_s()是vs下对scanf()的改进，scanf_s(“%s”, ws, 10);的意思是读入字符串到地址ws，最多读入10个字符
10分	ws[10] = *(ws+10); 你有吗? 你有没有? 你没有吧?
10分	char ws[10];//不行 wchar_t ws[10];//可以 %s String, up to first white-space character (space, tab or newline). To read strings not delimited by space characters, use set of square brackets ([ ]), as discussed in scanf Width Specification. When used with scanf functions, signifies single-byte character array; when used with wscanf functions, signifies wide-character array. In either case, character array must be large enough for input field plus terminating null character, which is automatically appended. %S Opposite-size character string, up to first white-space character (space, tab or newline). To read strings not delimited by space characters, use set of square brackets ([ ]), as discussed in scanf Width Specification. When used with scanf functions, signifies wide-character array; when used with wscanf functions, signifies single-byte–character array. In either case, character array must be large enough for input field plus terminating null character, which is automatically appended.
	Collapse AllExpand All Code: All Code: Multiple Code: Visual Basic Code: C# Code: Visual C++ Code: J# Code: JScript Visual Basic C# Visual C++ J# JScript Run-Time Library Reference scanf_s, _scanf_s_l, wscanf_s, _wscanf_s_l Example See Also Send Feedback Read formatted data from the standard input stream. These are versions of scanf, _scanf_l, wscanf, _wscanf_l with security enhancements as described in Security Enhancements in the CRT. int scanf_s( const char format [, argument]… ); int _scanf_s_l( const char format, locale_t locale [, argument]… ); int wscanf_s( const wchar_t format [, argument]… ); int _wscanf_s_l( const wchar_t format, locale_t locale [, argument]… ); Parameters format Format control string. argument Optional arguments. locale The locale to use. Return Value Returns the number of fields successfully converted and assigned; the return value does not include fields that were read but not assigned. A return value of 0 indicates that no fields were assigned. The return value is EOF for an error or if the end-of-file character or the end-of-string character is encountered in the first attempt to read a character. If format is a NULL pointer, the invalid parameter handler is invoked, as described in Parameter Validation. If execution is allowed to continue, scanf_s and wscanf_s return EOF and set errno to EINVAL. For information on these and other error codes, see _doserrno, errno, _sys_errlist, and _sys_nerr. Remarks The scanf_s function reads data from the standard input stream stdin and writes the data into the location given by argument. Each argument must be a pointer to a variable of a type that corresponds to a type specifier in format. If copying takes place between strings that overlap, the behavior is undefined. wscanf_s is a wide-character version of scanf_s; the format argument to wscanf_s is a wide-character string. wscanf_s and scanf_s behave identically identically if the stream is opened in ANSI mode. scanf_s doesn””t currently support input from a UNICODE stream. The versions of these functions with the _l suffix are identical except that they use the locale parameter passed in instead of the current thread locale. Unlike scanf and wscanf, scanf_s and wscanf_s require the buffer size to be specified for all input parameters of type c, C, s, S, or [. The buffer size is passed as an additional parameter immediately following the pointer to the buffer or variable. For example, if reading a string, the buffer size for that string is passed as follows: char s[10]; scanf(“%9s”, s, 10); The buffer size includes the terminating null. A width specification field may be used to ensure that the token read in will fit into the buffer. If no width specification field is used, and the token read is too big to fit in the buffer, nothing will be written to that buffer. Note: The size parameter is of type unsigned, not size_t. In the case of characters, one may read a single character as follows: char c; scanf(“%c”, &c, 1); When reading multiple characters for non-null terminated strings, integers are used as the width specification and the buffer size. char c[4]; scanf(“%4c”, &c, 4); // not null terminated For more information, see scanf Width Specification. TCHAR.H routine _UNICODE & _MBCS not defined _MBCS defined _UNICODE defined _tscanf_s scanf_s scanf_s wscanf_s _tscanf_s_l _scanf_s_l _scanf_s_l _wscanf_s_l For more information, see Format Specification Fields — scanf functions and wscanf Functions. Requirements Routine Required header scanf_s, _scanf_s_l <stdio.h> wscanf_s, _wscanf_s_l <stdio.h> or <wchar.h> For additional compatibility information, see Compatibility in the Introduction. Example Copy Code // crt_scanf_s.c // This program uses the scanf_s and wscanf_s functions // to read formatted input. #include <stdio.h> int main( void ) { int i, result; float fp; char c, s[81]; wchar_t wc, ws[81]; result = scanf_s( “%d %f %c %C %s %S”, &i, &fp, &c, 1, &wc, 1, s, 80, ws, 80 ); printf( “The number of fields input is %d\n”, result ); printf( “The contents are: %d %f %c %C %s %S\n”, i, fp, c, wc, s, ws); result = wscanf_s( L”%d %f %hc %lc %S %ls”, &i, &fp, &c, 2, &wc, 1, s, 80, ws, 80 ); wprintf( L”The number of fields input is %d\n”, result ); wprintf( L”The contents are: %d %f %C %c %hs %s\n”, i, fp, c, wc, s, ws); } Copy Code 71 98.6 h z Byte characters 36 92.3 y n Wide characters Copy Code The number of fields input is 6 The contents are: 71 98.599998 h z Byte characters The number of fields input is 6 The contents are: 36 92.300003 y n Wide characters .NET Framework Equivalent System::Console::Read System::Console::ReadLine See also Parse methods, such as System::Double::Parse. See Also Concepts Floating-Point Support Stream I/O Locale fscanf, _fscanf_l, fwscanf, _fwscanf_l printf, _printf_l, wprintf, _wprintf_l sprintf, _sprintf_l, swprintf, _swprintf_l, __swprintf_l sscanf, _sscanf_l, swscanf, _swscanf_l Send feedback on this topic to Microsoft.