is、isw 常式
__iscsym、__iswcsym、__iscsymf、__iswcsymf、_iscsym_l、_iswcsym_l、_iscsymf_l、_iswcsymf_l |
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備註
這些行程能測試在特殊情況下的字元。
is 常式產生有意義的結果對於由 -1 (EOF) 到 ( UCHAR_MAX 0xFF)。 必須是引數型別 int。
警告
若開頭為 is常式，傳遞型別為 char 的引數可能會產生無法預期的結果。一個值大於 0x7F 且型別為 char 的 SBCS 或 MBCS 單一位元組字元為負值。如果傳遞的是 char，則編譯器 (Compiler) 可能會將該值轉換成帶正負號 (Signed) 的 int 或帶正負號的 long。這個由編譯器進行 sign-extended 的值，可能會有未預期的結果。
isw 常式由 -1 (WEOF) 到 0xFFFF 會產生不同意義的結果。 wint_t 資料型別在 WCHAR.H 定義為 unsigned short;它可以表示所有寬字元或寬字元檔案結尾 (WEOF) 值。
輸出值受地區設定的LC_CTYPE 分類設定所影響。如需詳細資訊，請參閱 setlocale 。 這些函式沒有以 _l 後綴的版本在這些地區相依的行為上使用目前的地區設定，而以**_l** 後綴版本除了它們會使用傳入的地區設定參數之外運作相同。
在「C」地區設定， is 常式的測試條件如下:
isalnum
英數 (A-Z、a-z或 0–9)。isalpha
字母 (a-z、A-Z)。__isascii
ASCII 字元 (0x00 – 0x7F)。isblank
水平索引標籤或空白字元 (0x09 或 0x20)。iscntrl
控制字元 (0x00 – 0x1F 或 0x7F)。__iscsym
字母、底線或數字。__iscsymf
字母或底線。isdigit
十進位數字(0 – 9)。isgraph
可列印字元以外的空間 ( )。islower
小寫字母 (a – z)。isprint
可列印的字元包括空格 (0x20 – 0x7E)。ispunct
標點符號。isspace
空白字元 (0x09 – 0x0D 或 0x20)。isupper
大寫字母 (A – Z)。isxdigit
十六進位數字 (A-F, a-f, 0-9)。
對於 isw 常式，對於指定條件測試的結果與地區設定無關。 isw 函式的測試條件如下:
iswalnum
iswalpha 或 iswdigit。iswalpha
任何寬字元的設定一個由實作環境決定 iswcntrl、 iswdigit、 iswpunct或 iswspace 都不是非零。 iswalpha 傳回非零只有在寬字元 iswupper or iswlower i為非零。iswascii
ASCII 字元 (0x0000 – 0x007F) 的寬字元表示。iswblank
對應於標準空格字元或是一個由實作環境決定設定寬字元 iswalnum 是錯誤的寬字元。 標準空白字元是空白 (L' ') 和水平索引標籤 (L'\t')。iswcntrl
控制項寬字元。__iswcsym
isalnum 為 true 的任何寬字元或「_」字元。__iswcsymf
對於iswalpha 為 true 的任何寬字元或「_」字元。iswctype
字元具有 desc 引數所指定的屬性。 對於 iswctype之 desc 引數的每一個有效值，如下表所示，具有對等寬字元分類常式:iswctype 的相等性 ( c, desc ) 到其他 isw 測試行程
desc 引數的值
iswctype ( c， desc ) 相等
_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
與十進位數值字元對應的寬字元。iswgraph
可列印的寬字元以外的空間寬字元 (L' ')。iswlower
小寫字母或一個由實作環境決定 iswcntrl、 iswdigit、 iswpunct或 iswspace 都不是非零的設定寬字元。 只有當寬字元對應於小寫字母時，iswlower 傳回非零值。iswprint
可列印的寬字元，包含空間寬字元 (L' ')。iswpunct
可列印的寬字元不是 (L' ') 寬字元也不是 iswalnum 為非零值的寬字元。iswspace
對應於標準空格字元或是由實作環境決定設定寬字元 iswalnum 是錯誤的寬字元。 標準空白字元如下:空間 (L' ')，換頁字元 (L'\f')，新行字元 (L'\n')，歸位字元 (L'\r')，水平索引標籤 (L'\t') 和垂直索引標籤 (L'\v')。iswupper
大寫或是一個由實作環境決定設定寬字元 iswcntrl、 iswdigit、 iswpunct或 iswspace 都不是非零的寬字元。 只有當寬字元對應於大寫字母時，iswupper 傳回非零值。iswxdigit
對應至十六位元字元的寬字元。
範例
// 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 .