std::isalnum

 

C++

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Espressioni regolari (C++11)

Operazioni atomicche (C++11)

Multithreading (C++11)

 

Stringhe libreria

Null-stringhe terminate Original: Null-terminated strings The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

Byte stringhe

Multibyte stringhe

Stringhe larghe

Classi Original: Classes The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

basic_string

char_traits

 

Null-stringhe terminate byte

Funzioni Original: Functions The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
Carattere manipolazione Original: Character manipulation The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
isalnum isalpha islower isupper isdigit isxdigit isblank (C++11)	iscntrl isgraph isspace isprint ispunct tolower toupper
Le conversioni in formati numerici Original: Conversions to numeric formats The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
atof atoi atol atoll strtol strtoll	strtoul strtoull strtof strtod strtold
Della gestione delle stringhe Original: String manipulation The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
strcpy
strncpy
strcat
strncat
strxfrm
String esame Original: String examination The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
strlen strcmp strncmp strcoll strchr strrchr	strspn strcspn strpbrk strstr strtok
Memoria manipolazione Original: Memory manipulation The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
memchr
memcmp
memset
memcpy
memmove
Varie Original: Miscellaneous The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
strerror

 

Elemento definito nell'header <cctype>
int isalnum( int ch );

Controlla se il dato carattere è un carattere alfanumerico in base alla localizzazione corrente C, vale a dire un numero (0123456789 nelle impostazioni internazionali di default), una lettera maiuscola (ABCDEFGHIJKLMNOPQRSTUVWXYZ nelle impostazioni internazionali di default), o una lettera minuscola (abcdefghijklmnopqrstuvwxyz nelle impostazioni internazionali di default).

Original:

Checks if the given character is an alphanumeric character according to the current C locale, i.e. either a number (0123456789 in the default locale), an uppercase letter (ABCDEFGHIJKLMNOPQRSTUVWXYZ in the default locale), or a lowercase letter (abcdefghijklmnopqrstuvwxyz in the default locale).

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Parametri

ch

-

carattere Original: character The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

Valore di ritorno

Valore diverso da zero (true) se il carattere è un carattere alfanumerico, 0 (false) altrimenti.

Original:

Non-zero value (true) if the character is an alphanumeric character, 0 (false) otherwise.

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Esempio

Viene illustrato l'utilizzo di isalnum () con diverse impostazioni internazionali (OS-specifico) .

Original:

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

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#include <iostream>
#include <cctype>
#include <clocale>
 
int main()
{
    const char c = '\xdf'; // German letter ß in ISO-8859-1
 
    std::cout << "isalnum(\'\\xdf\', default C locale) returned "
               << std::boolalpha << (bool)std::isalnum(c) << '\n';
 
    std::setlocale(LC_ALL, "de_DE.iso88591");
    std::cout << "isalnum(\'\\xdf\', ISO-8859-1 locale) returned "
              << std::boolalpha << (bool)std::isalnum(c) << '\n';
 
}

Output:

isalnum('\xdf', default C locale) returned false
isalnum('\xdf', ISO-8859-1 locale) returned true

Vedi anche

isalnum(std::locale)	Verifica se un carattere è classificato come alfanumerico da un locale Original: checks if a character is classified as alphanumeric by a locale The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (funzione di modello)
iswalnum	Verifica se un carattere esteso è alfanumerico Original: checks if a wide character is alphanumeric The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (funzione)
C documentation for isalnum

ASCII values (hex)		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
0 - 8	0x00-0x08	control codes (NUL, etc.)	≠0	0	0	0	0	0	0	0	0	0	0	0
9	0x09	tab (\t)	≠0	0	≠0	≠0	0	0	0	0	0	0	0	0
10 - 13	0x0A-0x0D	whitespaces (\n,\v,\f,\r)	≠0	0	≠0	0	0	0	0	0	0	0	0	0
14 - 31	0x0E-0x1F	control codes	≠0	0	0	0	0	0	0	0	0	0	0	0
32	0x20	space	0	≠0	≠0	≠0	0	0	0	0	0	0	0	0
33 - 47	0x21-0x2F	!"#$%&'()*+,-./	0	≠0	0	0	≠0	≠0	0	0	0	0	0	0
48 - 57	0x30-0x39	0123456789	0	≠0	0	0	≠0	0	≠0	0	0	0	≠0	≠0
58 - 64	0x3a-0x40	:;<=>?@	0	≠0	0	0	≠0	≠0	0	0	0	0	0	0
65 - 70	0x41-0x46	ABCDEF	0	≠0	0	0	≠0	0	≠0	≠0	≠0	0	0	≠0
71 - 90	0x47-0x5A	GHIJKLMNOPQRSTUVWXYZ	0	≠0	0	0	≠0	0	≠0	≠0	≠0	0	0	0
91 - 96	0x5B-0x60	[\]^_`	0	≠0	0	0	≠0	≠0	0	0	0	0	0	0
97 -102	0x61-0x66	abcdef	0	≠0	0	0	≠0	0	≠0	≠0	0	≠0	0	≠0
103-122	0x67-0x7A	ghijklmnopqrstuvwxyz	0	≠0	0	0	≠0	0	≠0	≠0	0	≠0	0	0
123-126	0x7B-0x7E	{|}~	0	≠0	0	0	≠0	≠0	0	0	0	0	0	0
127	0x7F	backspace character (DEL)	≠0	0	0	0	0	0	0	0	0	0	0	0