iswalnum
Defined in header <wctype.h>
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||
---|---|---|
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(since C95) |
Checks if the given wide character is an alphanumeric character, i.e. either a number (0123456789
), an uppercase letter (ABCDEFGHIJKLMNOPQRSTUVWXYZ
), a lowercase letter (abcdefghijklmnopqrstuvwxyz
) or any alphanumeric character specific to the current locale.
Parameters
ch | - | wide character |
Return value
Non-zero value if the wide character is a alphanumeric character, zero otherwise.
Notes
ISO 30112 specifies which Unicode characters are include in POSIX alnum category.
Example
#include <stdio.h>
#include <wchar.h>
#include <wctype.h>
#include <locale.h>
int main(void)
{
wchar_t c = L'\u13ad'; // the Cherokee letter HA ('Ꭽ')
printf("in the default locale, iswalnum(%#x) = %d\n", c, !!iswalnum(c));
setlocale(LC_ALL, "en_US.utf8");
printf("in Unicode locale, iswalnum(%#x) = %d\n", c, !!iswalnum(c));
}
Output:
in the default locale, iswalnum(0x13ad) = 0
in Unicode locale, iswalnum(0x13ad) = 1
References
C11 standard (ISO/IEC 9899:2011):
- 7.30.2.1.1 The iswalnum function (p: 448)
C99 standard (ISO/IEC 9899:1999):
- 7.25.2.1.1 The iswalnum function (p: 394)
See also
checks if a character is alphanumeric (function) |
ASCII values | characters | iscntrl |
isprint |
isspace |
isblank |
isgraph |
ispunct |
isalnum
|
isalpha |
isupper |
islower |
isdigit |
isxdigit | ||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
decimal | hexadecimal | octal | |||||||||||||
0–8 | \x0 –\x8
|
\0 –\10
|
control codes (NUL , etc.)
|
≠0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
9 | \x9
|
\11
|
tab (\t )
|
≠0
|
0
|
≠0
|
≠0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
10–13 | \xA –\xD
|
\12 –\15
|
whitespaces (\n , \v , \f , \r )
|
≠0
|
0
|
≠0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
14–31 | \xE –\x1F
|
\16 –\37
|
control codes | ≠0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
32 | \x20
|
\40
|
space | 0
|
≠0
|
≠0
|
≠0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
33–47 | \x21 –\x2F
|
\41 –\57
|
!"#$%&'()*+,-./
|
0
|
≠0
|
0
|
0
|
≠0
|
≠0
|
0
|
0
|
0
|
0
|
0
|
0
|
48–57 | \x30 –\x39
|
\60 –\71
|
0123456789
|
0
|
≠0
|
0
|
0
|
≠0
|
0
|
≠0
|
0
|
0
|
0
|
≠0
|
≠0
|
58–64 | \x3A –\x40
|
\72 –\100
|
:;<=>?@
|
0
|
≠0
|
0
|
0
|
≠0
|
≠0
|
0
|
0
|
0
|
0
|
0
|
0
|
65–70 | \x41 –\x46
|
\101 –\106
|
ABCDEF
|
0
|
≠0
|
0
|
0
|
≠0
|
0
|
≠0
|
≠0
|
≠0
|
0
|
0
|
≠0
|
71–90 | \x47 –\x5A
|
\107 –\132
|
GHIJKLMNOP
|
0
|
≠0
|
0
|
0
|
≠0
|
0
|
≠0
|
≠0
|
≠0
|
0
|
0
|
0
|
91–96 | \x5B –\x60
|
\133 –\140
|
[\]^_`
|
0
|
≠0
|
0
|
0
|
≠0
|
≠0
|
0
|
0
|
0
|
0
|
0
|
0
|
97–102 | \x61 –\x66
|
\141 –\146
|
abcdef
|
0
|
≠0
|
0
|
0
|
≠0
|
0
|
≠0
|
≠0
|
0
|
≠0
|
0
|
≠0
|
103–122 | \x67 –\x7A
|
\147 –\172
|
ghijklmnop
|
0
|
≠0
|
0
|
0
|
≠0
|
0
|
≠0
|
≠0
|
0
|
≠0
|
0
|
0
|
123–126 | \x7B –\x7E
|
\172 –\176
|
}~ | 0
|
≠0
|
0
|
0
|
≠0
|
≠0
|
0
|
0
|
0
|
0
|
0
|
0
|
127 | \x7F
|
\177
|
backspace character (DEL )
|
≠0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
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