Question

Can somebody explain why next code output 26 timez ‘Z’ instead range from ‘A’ to ‘Z’, and how can I output this array correct. Look at code:

wchar_t *allDrvs[26];
    int count = 0;
     for (int n=0; n<26; n++)
     {
         wchar_t t[] = {L'A' + n, '\0'}; 
         allDrvs[n] = t;
         count++;
     }
     int j;
     for(j = 0; j < count; j++)
     {
        std::wcout << allDrvs[j] << std::endl;
     }

Answer 1

The problem (at least one) is:

{
     wchar_t t[] = {L'A' + n, '\0'}; 
     allDrvs[n] = t;  //allDrvs points to t
     count++;         
 }   //t is deallocated here
     //allDrvs[n] is a dangling pointer

So, short answer – undefined behavior on the line std::wcout << allDrvs[j].

To get a correct output – there’s a crappy ugly version involving dynamic allocation and copying between arrays.

Then there’s the correct version of using a std::vector<std::wstring> >.