以下代码的含义是什么？

Question

Could anyone tell me what is the meaning of the following code :

unsigned char  const *display_screen[] = {
    "\xfeXEPC Main Menu:\n\35System Status\n System Settings\n Access Control",    
    "\xfeXEPC Main Menu:\n System Status \n\35System Settings\n Access Control",
    "\xfeXEPC Main Menu:\n System Status \n System Settings\n\35Access Control",
    "\xfeXEPC Main Menu:\n\35Configuration\n Op.Programming\n Event Log  ",
    "\xfeXEPC Main Menu:\n Configuration\n\35Op.Programming\n Event Log  ",
    "\xfeXEPC Main Menu:\n Configuration\n Op.Programming\n\35Event Log  ",
    "\xfeXEPC Main Menu:\n\35History    ",
    "\xfeXEPC Main Menu:\n"};

Answer 1

The code is invalid. The string literals are of type char[N] (where N is the length of each string literal). These are implicitly convertible to char* but not to unsigned char* . Since the code is invalid, it doesn't have any meaning. :-)

If display_screen was a const char*[] instead of a const unsigned char*[] , this would declare display_screen as an array of const char* with the pointers in the array pointing to the string literals listed in the initializer.

Answer 2

Besides the signedness issue that James mentions, this defines an array of strings. The "\\xfe" at the beginning translate to hexadecimal value 0xfe and the "\\35" translates to octal 035 . The interpretation of these values is dependent of your platform.