Help with returning length of char variable.

I'm having some trouble returning the length of a char variable in a XOR encryption code.

Code:

#include <iostream>
#include <string>

using namespace std;

int main()
{
  int len;  
  string str2="A nice cat";
  len = str2.size();
  char str[len]=str2;
  char key[len]="ABCDEFGHIJ";
    for(int x=0; x<(len-1); x++)
    {
      str[x]=str[x]^key[x];
      cout  <<  str[x];
    }
  cout << "\n";
  system("PAUSE");
}

I am getting the errors:

variable-sized object 'str' may not be initialized.
variable-sized object 'key' may not be initialized.


Any ideas?

You can't have variable length array in C++. You would have to use dynamic allocation.

Why do you need to use character arrays at all? Just use the string, since operator[] returns a character just like it does for a character array.