is、isw 例程
__iscsym、__iswcsym、__iscsymf、__iswcsymf、_iscsym_l、_iswcsym_l、_iscsymf_l、_iswcsymf_l |
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备注
这些实例测试指定条件的字符。
is 实例产生从– 1 到 UCHAR_MAX (0xFF)，包含，所有整数参数的有意义的结果 (EOF)。 期望自变量类型为 int。
警告
对于以 is 的实例，传递类型为 char 的参数可能产生不可预知的结果。一个类型为 char 的 SBCS 或 MBCS 单字节字符的值大于 0x7F，则该值为负值。如果传递了一个 char，则编译器可能将该值转换为一个有符号的 int 或一个有符号的 long。编译器可能对该值进行符号扩展，从而产生意外的结果。
isw 实例产生从– 1 到 (WEOF) 到 0xFFFF，包含，所有整数值的有意义的结果。 wint_t 数据类型作在 WCHAR.H 定义为 unsigned short;它可以表示任何宽字符或宽字符文件结尾 (WEOF) 的值。
输出值受区域设置的 LC_CTYPE 类设置影响；有关更多信息，请参见 setlocale。 这些不带 _l 后缀的函数的版本使用为该区域设置相关的行为的当前区域设置；带有 _l 后缀的版本相同，只不过它们使用传递的区域设置参数。
在“C”区域设置，is 实例的测试条件如下所示：
isalnum
字母数字 (A – Z, a – z,或 0 – 9)。isalpha
按字母 (A – Z 或 a – z)。__isascii
ASCII 字符 (0x00 – 0x7F)。isblank
水平制表符或空格字符 (0x09 或 0x20)。iscntrl
控制字符 (0x00 – 0x1F 或 0x7F)。__iscsym
字母、下划线或数字。__iscsymf
字母或下划线。isdigit
十进制数字 (0 – 9)。isgraph
可打印字符除空格 ( )。islower
小写字母 (a – z)。isprint
可打印字符包括空格 (0x20 – 0x7E)。ispunct
标点字符。isspace
空格字符 (0x09 – 0x0D 或 0x20)。isupper
大写字母 (A – Z)。isxdigit
十六进制数字 (A-F，a-f 或 0 – 9)。
对于 isw 实例，指定的条件的测试的结果与区域设置无关。 isw 函数的测试条件如下所示：
iswalnum
iswalpha或 iswdigit。iswalpha
任何实现定义的宽字符设置那些 iswcntrl、iswdigit、iswpunct或 iswspace 都不是非零。 iswalpha 仅返回 iswupper 或 iswlower 的非零的宽字符的非零值。iswascii
宽字符代表ASCII 字符 (0x0000 – 0x007F) 。iswblank
对应于标准的空格字符或者是一个实现定义的一组宽字符的 iswalnum 是错误的宽字符。 标准空白符是空格 (L“) 和水平制表符 (L”\t”)。iswcntrl
控件宽字符。__iswcsym
isalnum 的任何宽字符或“_”字符是真的。__iswcsymf
iswalpha 的任何宽字符或“_”字符是真的。iswctype
字符具有 desc 参数特定的属性。 iswctype的 desc 参数的每个有效值，有等效的宽字符类别的实例，如下表所示：Equivalence of iswctype( c, desc ) to Other isw Testing Routines
desc 参数的值
iswctype ( c，desc ) 等效值
_ALPHA
iswalpha( c )
_ALPHA | _DIGIT
iswalnum( c )
_BLANK
iswblank( c )
_CONTROL
iswcntrl( c )
_DIGIT
iswdigit( c )
_ALPHA | _DIGIT | _PUNCT
iswgraph( c )
_LOWER
iswlower( c )
_ALPHA | _BLANK | _DIGIT | _PUNCT
iswprint( c )
_PUNCT
iswpunct( c )
_BLANK
iswblank( c )
_SPACE
iswspace( c )
_UPPER
iswupper( c )
_HEX
iswxdigit( c )
iswdigit
宽字符相对应与十进制数字字符。iswgraph
可打印宽字符除空格宽字符 (L“)。iswlower
小写字母或一个实现定义 iswcntrl、iswdigit、iswpunct或 iswspace 都不是非零的设置宽字符。 iswlower 仅返回非零对应于小写字母的宽字符。iswprint
可打印宽字符，包括空格宽字符 (L“)。iswpunct
iswalnum 中既不是空格宽字符 (L“) 也不是宽字符的打印宽字符是非零。iswspace
对应于标准的空格字符或者是一个实现定义的一组宽字符的 iswalnum 是错误的宽字符。 标准的空白字符：空格（L' '），换页（L'\f'），换行（L'\n'），回车（L'\r'），水平制表符（L'\t'），并垂直制表符（L'\v'）。iswupper
iswcntrl、iswdigit、iswpunct或 iswspace 其中的大写字符或是实现定义集合的宽字符都不是非零的宽字符。 iswupper 仅返回非零对应于大写字符的宽字符。iswxdigit
对应于十六进制数字字符的宽字符。
示例
// crt_isfam.c
/* This program tests all characters between 0x0
* and 0x7F, then displays each character with abbreviations
* for the character-type codes that apply.
*/
#include <stdio.h>
#include <ctype.h>
int main( void )
{
int ch;
for( ch = 0; ch <= 0x7F; ch++ )
{
printf( "%.2x ", ch );
printf( " %c", isprint( ch ) ? ch : ' ' );
printf( "%4s", isalnum( ch ) ? "AN" : "" );
printf( "%3s", isalpha( ch ) ? "A" : "" );
printf( "%3s", __isascii( ch ) ? "AS" : "" );
printf( "%3s", iscntrl( ch ) ? "C" : "" );
printf( "%3s", __iscsym( ch ) ? "CS " : "" );
printf( "%3s", __iscsymf( ch ) ? "CSF" : "" );
printf( "%3s", isdigit( ch ) ? "D" : "" );
printf( "%3s", isgraph( ch ) ? "G" : "" );
printf( "%3s", islower( ch ) ? "L" : "" );
printf( "%3s", ispunct( ch ) ? "PU" : "" );
printf( "%3s", isspace( ch ) ? "S" : "" );
printf( "%3s", isprint( ch ) ? "PR" : "" );
printf( "%3s", isupper( ch ) ? "U" : "" );
printf( "%3s", isxdigit( ch ) ? "X" : "" );
printf( ".\n" );
}
}
Output
00 AS C .
01 AS C .
02 AS C .
03 AS C .
04 AS C .
05 AS C .
06 AS C .
07 AS C .
08 AS C .
09 AS C S .
0a AS C S .
0b AS C S .
0c AS C S .
0d AS C S .
0e AS C .
0f AS C .
10 AS C .
11 AS C .
12 AS C .
13 AS C .
14 AS C .
15 AS C .
16 AS C .
17 AS C .
18 AS C .
19 AS C .
1a AS C .
1b AS C .
1c AS C .
1d AS C .
1e AS C .
1f AS C .
20 AS S PR .
21 ! AS G PU PR .
22 " AS G PU PR .
23 # AS G PU PR .
24 $ AS G PU PR .
25 % AS G PU PR .
26 & AS G PU PR .
27 ' AS G PU PR .
28 ( AS G PU PR .
29 ) AS G PU PR .
2a * AS G PU PR .
2b + AS G PU PR .
2c , AS G PU PR .
2d - AS G PU PR .
2e . AS G PU PR .
2f / AS G PU PR .
30 0 AN AS CS D G PR X.
31 1 AN AS CS D G PR X.
32 2 AN AS CS D G PR X.
33 3 AN AS CS D G PR X.
34 4 AN AS CS D G PR X.
35 5 AN AS CS D G PR X.
36 6 AN AS CS D G PR X.
37 7 AN AS CS D G PR X.
38 8 AN AS CS D G PR X.
39 9 AN AS CS D G PR X.
3a : AS G PU PR .
3b ; AS G PU PR .
3c < AS G PU PR .
3d = AS G PU PR .
3e > AS G PU PR .
3f ? AS G PU PR .
40 @ AS G PU PR .
41 A AN A AS CS CSF G PR U X.
42 B AN A AS CS CSF G PR U X.
43 C AN A AS CS CSF G PR U X.
44 D AN A AS CS CSF G PR U X.
45 E AN A AS CS CSF G PR U X.
46 F AN A AS CS CSF G PR U X.
47 G AN A AS CS CSF G PR U .
48 H AN A AS CS CSF G PR U .
49 I AN A AS CS CSF G PR U .
4a J AN A AS CS CSF G PR U .
4b K AN A AS CS CSF G PR U .
4c L AN A AS CS CSF G PR U .
4d M AN A AS CS CSF G PR U .
4e N AN A AS CS CSF G PR U .
4f O AN A AS CS CSF G PR U .
50 P AN A AS CS CSF G PR U .
51 Q AN A AS CS CSF G PR U .
52 R AN A AS CS CSF G PR U .
53 S AN A AS CS CSF G PR U .
54 T AN A AS CS CSF G PR U .
55 U AN A AS CS CSF G PR U .
56 V AN A AS CS CSF G PR U .
57 W AN A AS CS CSF G PR U .
58 X AN A AS CS CSF G PR U .
59 Y AN A AS CS CSF G PR U .
5a Z AN A AS CS CSF G PR U .
5b [ AS G PU PR .
5c \ AS G PU PR .
5d ] AS G PU PR .
5e ^ AS G PU PR .
5f _ AS CS CSF G PU PR .
60 ` AS G PU PR .
61 a AN A AS CS CSF G L PR X.
62 b AN A AS CS CSF G L PR X.
63 c AN A AS CS CSF G L PR X.
64 d AN A AS CS CSF G L PR X.
65 e AN A AS CS CSF G L PR X.
66 f AN A AS CS CSF G L PR X.
67 g AN A AS CS CSF G L PR .
68 h AN A AS CS CSF G L PR .
69 i AN A AS CS CSF G L PR .
6a j AN A AS CS CSF G L PR .
6b k AN A AS CS CSF G L PR .
6c l AN A AS CS CSF G L PR .
6d m AN A AS CS CSF G L PR .
6e n AN A AS CS CSF G L PR .
6f o AN A AS CS CSF G L PR .
70 p AN A AS CS CSF G L PR .
71 q AN A AS CS CSF G L PR .
72 r AN A AS CS CSF G L PR .
73 s AN A AS CS CSF G L PR .
74 t AN A AS CS CSF G L PR .
75 u AN A AS CS CSF G L PR .
76 v AN A AS CS CSF G L PR .
77 w AN A AS CS CSF G L PR .
78 x AN A AS CS CSF G L PR .
79 y AN A AS CS CSF G L PR .
7a z AN A AS CS CSF G L PR .
7b { AS G PU PR .
7c | AS G PU PR .
7d } AS G PU PR .
7e ~ AS G PU PR .
7f AS C .