.NET Information center: What are TCHAR, WCHAR, LPSTR, LPWSTR, LPCTSTR (etc.)?

Sunday, March 11, 2012

What are TCHAR, WCHAR, LPSTR, LPWSTR, LPCTSTR (etc.)?

Many C++ Windows programmers get confused over what bizarre identifiers like TCHAR, LPCTSTR are. Here, in brief, I would try to clear out the fog.

In general, a character can be 1 byte or 2 bytes. Let's say 1-byte character is ANSI, using which English characters are represented. And let's say 2-byte character is Unicode, which can represent ALL languages in the world.

VC++ support char and wchar_t as native datatypes for ANSI and Unicode characters respectively.

What if you want your C/C++ program to be Character-mode independent?

Use generic characters. That means, instead of replacing:

char cResponse; // 'Y' or 'N'

char sUsername[64];

// str* functions

with

wchar_t cResponse; // 'Y' or 'N'

wchar_t sUsername[64];

// wcs* functions

You can simply code it:

#include<TCHAR.H> // Implicit or explicit include

TCHAR cResponse; // 'Y' or 'N'

TCHAR sUsername[64];

// _tcs* functions

Thus, when your project is being compiled as Unicode, the TCHAR would translate to wchar_t. If it is being compiled as ANSI/MBCS, it would be translated to char. Likewise, instead of using strcpy, strlen, strcat (including the secure versions suffixed with _s); or wcscpy, wcslen, wcscat (including secure), you can simply use _tcscpy, _tcslen, _tcscat functions.