C++ - char vs. wchar_t

char and wchar_t are character data types in C++.

• char (character)

  • char is an 8-bit character data type.
  • char is for ANSI text.
  • CHAR is a typedef for char.
  • char* is used with Win32 ANSI ('A') functions. E.g. MessageBoxA().
• wchar_t (wide character)

  • wchar_t is a 16-bit character data type.
  • wchar_t is for Unicode text. Specifically UTF-16.
  • WCHAR is a typedef for wchar_t.
  • wchar_t* is used with Win32 WIDE ('W') functions. E.g. MessageBoxW().

  #include <windows.h>
 
  MessageBoxA(HWND hWnd, const char* text, const char* caption, UINT uType);
 
  MessageBoxW(HWND hWnd, const wchar_t* text, const wchar_t* caption, UINT uType);
  

  #include <string>
  #include <tchar.h>
  
  // ansi
  char message_a[] = "hello";
  auto len_a = strlen(message_a); // len = 5 chars
  auto size_a = sizeof(message_a); // size = 6 bytes (includes terminating null character)
  
  // wide
  wchar_t message_w[] = L"hello";
  auto len_w = wcslen(message_w); // len = 5 chars
  auto size_w = sizeof(message_w); // size = 12 bytes (includes terminating null character)
  

  // typedef declaration synonym
  typedef char CHAR;
  typedef wchar_t WCHAR;