From cppreference.com
intisgraph(intch);Checks if the given character is graphic (has a graphical representation) as classified by the currently installed C locale. In the default C locale, the following characters are graphic:
digits (0123456789)
uppercase letters (ABCDEFGHIJKLMNOPQRSTUVWXYZ)
lowercase letters (abcdefghijklmnopqrstuvwxyz)
punctuation characters (!"#$%&'()*+,-./:;<=>?@[\]^_`{|}~)
The behavior is undefined if the value of ch is not representable as unsignedchar and is not equal to EOF.
Parameters
ch - character to classify Return value
Non-zero value if the character has a graphical representation character, zero otherwise.
Notes
Like all other functions from
, the behavior of std::isgraph is undefined if the argument's value is neither representable as unsignedchar nor equal to EOF. To use these functions safely with plain chars (or signedchars), the argument should first be converted to unsignedchar:
boolmy_isgraph(charch){returnstd::isgraph(static_cast<unsignedchar>(ch));}Similarly, they should not be directly used with standard algorithms when the iterator's value type is char or signedchar. Instead, convert the value to unsignedchar first:
intcount_graphs(conststd::string&s){returnstd::count_if(s.begin(),s.end(),// static_cast<int(*)(int)>(std::isgraph) // wrong// [](int c){ return std::isgraph(c); } // wrong// [](char c){ return std::isgraph(c); } // wrong[](unsignedcharc){returnstd::isgraph(c);}// correct);}Example
Run this code
#include<cctype>#include<clocale>#include<iostream>intmain(){unsignedcharc='\xb6';// the character ¶ in ISO-8859-1std::cout<<"isgraph(\'\\xb6\', default C locale) returned "<<std::boolalpha<<(std::isgraph(c)!=0)<<'\n';std::setlocale(LC_ALL,"en_GB.iso88591");std::cout<<"isgraph(\'\\xb6\', ISO-8859-1 locale) returned "<<std::boolalpha<<(std::isgraph(c)!=0)<<'\n';}Possible output:
isgraph('\xb6', default C locale) returned false isgraph('\xb6', ISO-8859-1 locale) returned true See also
ASCII values characters
decimal hexadecimal octal 0–8 \x0–\x8\0–\10control codes (NUL, etc.) ≠0000000000009 \x9\11tab (\t) ≠00≠0≠00000000010–13 \xA–\xD\12–\15whitespaces (\n, \v, \f, \r) ≠00≠000000000014–31 \xE–\x1F\16–\37control codes ≠00000000000032 \x20\40space 0≠0≠0≠00000000033–47 \x21–\x2F\41–\57!"#$%&'()*+,-./0≠000≠0≠000000048–57 \x30–\x39\60–\7101234567890≠000≠00≠0000≠0≠058–64 \x3A–\x40\72–\100:;<=>?@0≠000≠0≠000000065–70 \x41–\x46\101–\106ABCDEF0≠000≠00≠0≠0≠000≠071–90 \x47–\x5A\107–\132GHIJKLMNOP
QRSTUVWXYZ0≠000≠00≠0≠0≠000091–96 \x5B–\x60\133–\140[\]^_`0≠000≠0≠000000097–102 \x61–\x66\141–\146abcdef0≠000≠00≠0≠00≠00≠0103–122 \x67–\x7A\147–\172ghijklmnop
qrstuvwxyz0≠000≠00≠0≠00≠000123–126 \x7B–\x7E\172–\176{|}~0≠000≠0≠0000000127 \x7F\177backspace character (DEL) ≠000000000000