Check if string is empty

Question

I got a project in C++ which I need to edit. This is a declaration of variable:

LPSTR hwndTitleValue = (LPSTR)GlobalAlloc(GPTR,(sizeof(CHAR) * hwndTitleSize));

How to check if this string is empty?

I tried simply with if(hwndTitleValue == "") but it always returns false. How to check if this string is empty?

EDIT

I also need to check if the file is attached. Here is the code of the file:

    // Attachment
    OFSTRUCT ofstruct;
    HFILE hFile = OpenFile( mmsHandle->hTemporalFileName , &ofstruct , OF_READ );
    DWORD hFileSize = GetFileSize( (HANDLE) hFile , NULL );
    LPSTR hFileBuffer = (LPSTR)GlobalAlloc(GPTR, sizeof(CHAR) * hFileSize );
    DWORD hFileSizeReaded = 0;
    ReadFile( (HANDLE) hFile , hFileBuffer, hFileSize, &hFileSizeReaded, NULL );
    CloseHandle( (HANDLE) hFile );

How to check if hFile is empty?

Answer 1

The easiest way to check if a string is empty is to see if the first character is a null byte:

if( hwndTitleValue != NULL && hwndTitleValue[0] == '\0' ) {
    // empty
}

You can use strlen or strcmp as in other answers, but this saves a function call.