Hard coding a Unicode string is mostly a matter of deciding how you want to enter the string in your source editor. C++ provides a wide-character type, wchar_t, which can store Unicode strings. The exact implementation of wchar_t is implementation defined, but it is often UTF-32. The class wstring, defined in , is a sequence of wchar_ts, just like the string class is a sequence of chars. (Strictly speaking, of course, wstring is a typedef for basic_string<wchar_t>).
The easiest way to enter Unicode characters is to use the L prefix to a string literal, as stated in below code:
wstring ws1 = L”Infinity: \u2210″; // Use the code itself
wstring ws2 = L”Euro: “; // Or just type it in
Now, you can write these wide-character strings to a wide-character stream, like this:
wcout << ws1 << endl; // wcout is the wide char version of cout
This goes for files, too:
out << ws2 << endl;
The trickiest part of dealing with different character encodings isn’t embedding the right characters in your source files, it’s knowing what kind of character data you are getting back from a database, HTTP request, user input, and so on, and this is beyond the realm of the C++ standard. The C++ standard does not require a particular encoding, rather that the character encoding used by your operating system to store source files can be anything, as long as it supports at least the 96 characters used by the C++ language. For characters that are not part of this character set, called the basic source character set, the standard indicates that they must be available by using the \uXXXX or \UXXXXXXXX escape sequences, where each X is a hexadecimal digit.
Do this by hard coding the string with a prefix of L and typing the character into your source editor as you would any other string, or use the hexadecimal number that represents the Unicode character you’re after. Below code shows how to do it both ways.
using namespace std;
int main( )
// Create some strings with Unicode characters
wstring ws1 = L"Infinity: \u221E";
wstring ws2 = L"Euro: _";
wchar_t w = L"Infinity: \u221E";
out << ws2 << endl;
wcout << ws2 << endl;
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