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iswalnum

From cppreference.com
< c‎ | string‎ | wide
Defined in header <wctype.h>
int iswalnum( wint_t ch );
(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.

Contents

[edit] Parameters

ch - wide character

[edit] Return value

Non-zero value if the wide character is an alphanumeric character, zero otherwise.

[edit] Notes

ISO 30112 specifies which Unicode characters are include in POSIX alnum category.

[edit] Example

#include <stdio.h>
#include <locale.h>
#include <wchar.h>
#include <wctype.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));
}

Possible output:

in the default locale, iswalnum(0x13ad) = 0
in Unicode locale, iswalnum(0x13ad) = 1

[edit] References

  • C23 standard (ISO/IEC 9899:2023):
  • TBD The iswalnum function (p: TBD)
  • C17 standard (ISO/IEC 9899:2018):
  • 7.30.2.1.1 The iswalnum function (p: 327)
  • 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)

[edit] See also

checks if a character is alphanumeric
(function) [edit]
C++ documentation for iswalnum
ASCII values characters

iscntrl
iswcntrl

isprint
iswprint

isspace
iswspace

isblank
iswblank

isgraph
iswgraph

ispunct
iswpunct

isalnum
iswalnum

isalpha
iswalpha

isupper
iswupper

islower
iswlower

isdigit
iswdigit

isxdigit
iswxdigit

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
QRSTUVWXYZ
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
qrstuvwxyz
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