From 754bbf7a25a8dda49b5d08ef0d0443bbf5af0e36 Mon Sep 17 00:00:00 2001 From: Craig Jennings Date: Sun, 7 Apr 2024 13:41:34 -0500 Subject: new repository --- devdocs/c/string%2Fbyte%2Fisalnum.html | 124 +++++++++++++++++++++++++++++++++ 1 file changed, 124 insertions(+) create mode 100644 devdocs/c/string%2Fbyte%2Fisalnum.html (limited to 'devdocs/c/string%2Fbyte%2Fisalnum.html') diff --git a/devdocs/c/string%2Fbyte%2Fisalnum.html b/devdocs/c/string%2Fbyte%2Fisalnum.html new file mode 100644 index 00000000..98f04421 --- /dev/null +++ b/devdocs/c/string%2Fbyte%2Fisalnum.html @@ -0,0 +1,124 @@ +

isalnum

Defined in header <ctype.h> 
int isalnum( int ch );
+

Checks if the given character is an alphanumeric character as classified by the current C locale. In the default locale, the following characters are alphanumeric:

+

The behavior is undefined if the value of ch is not representable as unsigned char and is not equal to EOF.

+

Parameters

+ +
ch - character to classify

Return value

Non-zero value if the character is an alphanumeric character, 0 otherwise.

+

Example

+

Demonstrates the use of isalnum with different locales (OS-specific).

+
#include <stdio.h>
+#include <ctype.h>
+#include <locale.h>
+ 
+int main(void)
+{
+    unsigned char c = '\xdf'; // German letter ß in ISO-8859-1
+ 
+    printf("isalnum('\\xdf') in default C locale returned %d\n", !!isalnum(c));
+ 
+    if(setlocale(LC_CTYPE, "de_DE.iso88591"))
+        printf("isalnum('\\xdf') in ISO-8859-1 locale returned %d\n", !!isalnum(c));
+}

Possible output:

+
isalnum('\xdf') in default C locale returned 0
+isalnum('\xdf') in ISO-8859-1 locale returned 1

References

See also

+ +
+
(C95)
 checks if a wide character is alphanumeric
(function)
C++ documentation for isalnum
+ + + + + + + + + + + + + + + + + +
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
+

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Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.
+ https://en.cppreference.com/w/c/string/byte/isalnum +

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