Xor char*

I want to xor string with prepared key before :

Code:

unsigned char key[8];
char *text;
text = "testtesttesttest";

srand ( time(NULL) );
int lowest=0, highest=255;
int range=(highest-lowest)+1; 
for(int index=0; index<8; index++){ 
   key[index] = lowest+int(range*rand()/(RAND_MAX + 1.0));
}

for(int a=0; text[a] != NULL; a++)
{
    text[a] ^= key[a%8];        
}

I was programming in delphi before and i had byte type which is unsigned char here as i read. Conversion was pretty easy but don't know how to do that in C++.

What's the problem? The code seems to be correct, despite of the fact that:

Code:

char *text;
text = "testtesttesttest";

Should be:

Code:

char text[] = "testtesttesttest";

Better yet,

Code:

char *text;
text = "testtesttesttest";

...can be changed to...

Code:

std::string text = "testtesttesttest";

"Incorrect" is not the word for it as it is not incorrect to use a null-terminated character array, it's just possibly more error prone.
I've been seeing a loss of distinction between fact and opinion lately from Elysia, which disappoints me a little.

FYI, it's like the distinction between array [0..X] of char and string in Delphi, though in C++ you don't need to use StrPas to convert from array of char to string.