std::isalnum
Da cppreference.com.
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Elemento definito nell'header <cctype>
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int isalnum( int ch ); |
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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).The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
You can help to correct and verify the translation. Click here for instructions.
Indice |
[modifica] 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. |
[modifica] 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.The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
You can help to correct and verify the translation. Click here for instructions.
[modifica] Esempio
Viene illustrato l'utilizzo di isalnum () con diverse impostazioni internazionali (OS-specifico) .
Original:
Demonstrates the use of isalnum() with different locales (OS-specific).
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
You can help to correct and verify the translation. Click here for instructions.
#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
[modifica] Vedi anche
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) | |
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
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ASCII values (hex) |
characters |
isalnum |
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0 - 8 | 0x00-0x08
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control codes (NUL , etc.)
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≠0
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0
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0
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0
|
0
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0
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0
|
0
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0
|
0
|
0
|
0
|
9 | 0x09
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tab (\t )
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≠0
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0
|
≠0
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≠0
|
0
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0
|
0
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0
|
0
|
0
|
0
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0
|
10 - 13 | 0x0A-0x0D
|
whitespaces (\n ,\v ,\f ,\r )
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≠0
|
0
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≠0
|
0
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0
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0
|
0
|
0
|
0
|
0
|
0
|
0
|
14 - 31 | 0x0E-0x1F
|
control codes | ≠0
|
0
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0
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0
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0
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0
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0
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0
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0
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0
|
0
|
0
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32 | 0x20
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space | 0
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≠0
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≠0
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≠0
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0
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0
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0
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0
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0
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0
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0
|
0
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33 - 47 | 0x21-0x2F
|
!"#$%&'()*+,-./
|
0
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≠0
|
0
|
0
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≠0
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≠0
|
0
|
0
|
0
|
0
|
0
|
0
|
48 - 57 | 0x30-0x39
|
0123456789
|
0
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≠0
|
0
|
0
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≠0
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0
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≠0
|
0
|
0
|
0
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≠0
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≠0
|
58 - 64 | 0x3a-0x40
|
:;<=>?@
|
0
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≠0
|
0
|
0
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≠0
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≠0
|
0
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0
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0
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0
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0
|
0
|
65 - 70 | 0x41-0x46
|
ABCDEF
|
0
|
≠0
|
0
|
0
|
≠0
|
0
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≠0
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≠0
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≠0
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0
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0
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≠0
|
71 - 90 | 0x47-0x5A
|
GHIJKLMNOPQRSTUVWXYZ
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0
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≠0
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0
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0
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≠0
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0
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≠0
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≠0
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≠0
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0
|
0
|
0
|
91 - 96 | 0x5B-0x60
|
[\]^_`
|
0
|
≠0
|
0
|
0
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≠0
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≠0
|
0
|
0
|
0
|
0
|
0
|
0
|
97 -102 | 0x61-0x66
|
abcdef
|
0
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≠0
|
0
|
0
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≠0
|
0
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≠0
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≠0
|
0
|
≠0
|
0
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≠0
|
103-122 | 0x67-0x7A
|
ghijklmnopqrstuvwxyz
|
0
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≠0
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0
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0
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≠0
|
0
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≠0
|
≠0
|
0
|
≠0
|
0
|
0
|
123-126 | 0x7B-0x7E
|
{|}~
|
0
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≠0
|
0
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0
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≠0
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≠0
|
0
|
0
|
0
|
0
|
0
|
0
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127 | 0x7F
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backspace character (DEL )
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≠0
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0
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0
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0
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0
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0
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0
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0
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0
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0
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0
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0
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