[number]-F appearing at the end of char?
===

I am a new to c++ and was butchering together a palindrome program at 1am on a Sunday just, because! and I have come across this problem:

Input: test
Reverse: tset3-F

Where has the 3-F come from? Sometimes it's just -F or another number-F. Where is this coming from?

Here is my code:

     #include <iostream>
     #include <string>


     using namespace std;

    int main() {

     string eString;
     
     int length;
     int counter = 0;
    
     cout << "Enter String: ";
     cin >> eString;
    
     length = eString.length();
    
    
     char reverseChar[length];
     
    
     
    
      for(int x = eString.length() -1; x > -1; x--) {
    
         reverseChar[counter] = eString[x];
     
         counter++;
     
     }
     cout << "Reverse: " << reverseChar;


      }


Many thanks for your time.
