For a console application, I need to display the symbol: √
When I try to simply output it using:
std::cout << '√' << std::endl; or
std::wcout << '√' << std::endl;,
it outputs the number 14846106 instead.
I've tried searching for an answer and have found several recommendations of the following:
std::cout << "\xFB" << std::endl; and
std::cout << (unsigned char)251 << std::endl;
which both display a superscript 1.
This is using the Windows console with Lucida font. I've tried this with various character pages and always get the same superscript 1. When I try to find its value through getchar() or cin, the symbol is converted into the capital letter V. I am, however, sure that it can display this character simply by pasting it in. Is there an easy way of displaying Unicode characters?
Actually "\xFB" or (unsigned char)251 are the same and do correspond to the root symbol √... but not in the Lucida font and other typefaces ASCII table , where it is an ¹ (superscript 1).
Switching to Unicode with the STL is a possibility, but I doubt it will run on Windows...
#include <iostream>
#include <locale.h>
int main() {
std::locale::global(std::locale("en_US.UTF8"));
std::wcout.imbue(std::locale());
wchar_t root = L'√';
std::wcout << root << std::endl;
return 0;
}
Since this will not satisfy you, here a portable Unicode library: http://site.icu-project.org/
Related
I am trying to represent 8 bit numbers with characters and I don't want to have to use an int to define the character, I want to use the actual character symbol. But when I use standard ASCII codes, everything outside of the range 32-100 something are completely different.
So I looped through all 256 ascii codes and printed them, for instance it said that this character '±' is code 241. But when I copy and paste that symbol from the console, or even use the alt code, it says that character is code -79... How can I get these two things to match up? Thank you!
It should be a problem of codepage. Windows console applications have a codepage that "maps" the 0-255 characters to a subset of Unicode characters. It is something that exists from the pre-Unicode era to support non-american character sets. There are some Windows API to select the codepage for the console: SetConsoleOutputCP (and SetConsoleCP for input)
#include <iostream>
#define WIN32_LEAN_AND_MEAN
#include <Windows.h>
int main() {
unsigned int cp = ::GetConsoleOutputCP();
std::cout << "Default cp of console: " << cp << std::endl;
::SetConsoleCP(28591);
::SetConsoleOutputCP(28591);
cp = ::GetConsoleOutputCP();
std::cout << "Now the cp of console is: " << cp << std::endl;
for (int i = 32; i < 256; i++) {
std::cout << (char)i;
if (i % 32 == 31) {
std::cout << std::endl;
}
}
}
The 28591 codepage is the iso-8859-1 codepage that maps the 0-255 characters to the unicode 0-255 codepoints (the 28591 number is taken from https://learn.microsoft.com/en-us/windows/win32/intl/code-page-identifiers)
This is a follow up question to:
std::isgraph asserts, how to fix?
After setting locale to "en_US.UTF-8", std::isgraph no longer asserts.
However, the unicode character 架 (U+67B6) is reported as false in the same function. What is going on ?
It's a unicode built on Windows platform.
If you want to test characters that are too large to fit in an unsigned char, you can try using the wide-character versions, or a Unicode library as already suggested (Which is really the better option for portable code, as it removes any system or locale based differences in behavior).
This program:
#include <clocale>
#include <cwctype>
#include <iostream>
int main() {
wchar_t x = L'\u67B6';
char *loc = std::setlocale(LC_CTYPE, "");
std::wcout << "Using locale " << loc << ".\n";
std::wcout << "Character " << x << " is graphical: " << std::boolalpha
<< static_cast<bool>(std::iswgraph(x)) << '\n';
return 0;
}
when compiled and ran on my Ubuntu test system, outputs
Using locale en_US.utf8.
Character 架 is graphical: true
You said you're using Windows, but I don't have a Windows computer available for testing, so I can't confirm if this'll work there or not.
std::isgraph is not a Unicode-aware function.
It's an antiquity from C.
From the documentation:
The behavior is undefined if the value of ch is not representable as unsigned char and is not equal to EOF.
It only takes int because .. it's an antiquity from C. Just like std::tolower.
You should be using something like ICU instead.
I've been trying to print Chinese Characters in C++. I've already searched around in the Internet, some said that you have to use wcout, others have suggested other methods. I've also stumbled on this post, where someone uses a piece of code:
#include <iostream>
int main()
{
char x[] = "中";
char y[] = u8"中";
wchar_t z = L'中';
char16_t b = u'\u4e2d';
char32_t a = U'\U00004e2d';
std::cout << x << '\n';
std::cout << y << '\n';
std::wcout << z << '\n';
std::cout << a << '\n';
std::cout << b << '\n';
}
which, on an internet site that shows the output of C++ code, prints:
中
中
-
20013
20013
However, for me it just prints
õ©¡
õ©¡
20013
20013
I'm using JetBrains CLion, with encoding set to UTF-8. However, I've also tried Visual Studio and QT Creator, I get the same result. I hope someone can help me out.
If you're using OSX Terminal maybe you can check the Encoding.
Terminal -> Preferences -> Encodings Tab
Then check if Traditional Chinese is checked or Unicode (UTF-8).
For Windows, you can try this, to change to UTF-8 encoding.
Go to Start then Run "regedit" -> Navigate to [HKEY_LOCAL_MACHINE\Software\Microsoft\Command Processor\Autorun] -> modify value to "chcp 65001"
Hope this helps.
The Problem
I'm developing an 32 bit unmanaged application in C++ on Windows using Visual Studio 2010. Forgive my lack of Windows knowledge as I usually develop on *nix.
Initially, in my program my calls to std::cout's stream insertion operator work fine. For example, the following statement outputs as expected:
std::cout << "hello" << std::endl;
However, the following code does not work:
std::cout << "\thello" << std::endl;
...call to DLL from Japanese company who won't respond to support requests...
std::cout << "\thello" << std::endl;
The above code prints:
hello
(inverted diamond symbol)hello(eighth note music symbol)(inverted o symbol)
Once I have called this DLL for the first time my output to std::cout is forever messed up. The symbols that are printed are not found in an ASCII table. The inverted o symbol is a single unicode char that looks like the letter 'o' but the black part of the o is white, and the white part is black(inverted colors). The music symbol is the unicode 8th note character.
Any ideas on why this is happening and how to fix it? It seems that this DLL is messing up how control characters (chars starting with \) are outputted.
What I have tried so far
I thought this might be a locale issue since the DLL is from a Japanese company. However, after the DLL call the locale is still "C" just as it was before the call. I use the following to query the locale:
printf ("Locale is: %s\n", setlocale(LC_ALL,NULL) );
I also thought this might be some kind of bizarre memory corruption but it seems that the \r\n gets replaced by (music symbol)(inverted o) whereas \t gets replaced by an inverted diamond symbol. There seems to be a regular "replace A by B" pattern for all the control chars, which would not indicate memory corruption.
Lastly, I also tried this:
std::cout << "blah" << '\r' << '\n';
and I see the same garbage characters created by:
std::cout << "blah" << std::endl;
Thanks in advance for any help and insight.
See whether this fixes it:
#include <iostream>
#include <locale>
int main()
{
std::cout << "\thello" << std::endl;
// ...call to DLL from Japanese company who won't respond to support requests...
locale mylocale(""); // or "C" // Construct locale object with the user's default preferences
std::cout.imbue( mylocale ); // Imbue that locale
std::cout << "\thello" << std::endl;
return 0;
}
Consult the documentation for that library whether
the change of locale is by design
it can be configured otherwise
You could perhaps associate another stream with cout
std::ostream cout2;
cout2.rdbuf(std::cout.rdbuf());
And use it. I'm sure that won't be thread safe. Flushing might be 'awkward' - but it should work
Is it possible to print subscripts/superscripts ?
for example like that : x²
what are functions allow to do that ?
This depends entirely on the environment you're running in. For a GUI system (Windows, Mac, Qt, etc.) you would need to consult the API documentation. For a text mode system, the best you could do is use specific characters in your current encoding. For instance, unicode has certain code points that are super- or sub-scripts of other characters.
If you're using a GUI, you can change the size and orientation of the font.
There are also superscript and subscript characters available in Unicode that could be used.
You can print the appropriate Unicode symbol, to cout or wcout depending on locale:
#include <iostream>
int main()
{
std::cout << "x\u00b2" << std::endl;
}
or
#include <iostream>
#include <locale>
int main()
{
std::locale::global(std::locale("de_DE.UTF8"));
std::wcout << L"x\u00b2" << std::endl;
}