XOR wrong result , escaping char - c++

Question

I am trying to xor a small string , it works . When I try to use the XORed string , I can't even compile it.
string str = "MyNameIsMila";
string str_xored = "2*&.8"'*"; //you can't escape this or the result be be different
//Enc:2*&.8"'*:
//Dec:MyNameIsMila:
I tried to escape the string , but then I have another result at the end.
Any good direction for this ?
Output after escaping:
//Enc:yamesila:
//Dec:2*&.8"'*:
Hoped to get MyNameIsMila back.
The function looks like :
string encryptDecrypt(string toEncrypt) {
char key = 'K'; //Any char will work
string output = toEncrypt;
for (int i = 0; i < toEncrypt.size(); i++)
output[i] = toEncrypt[i] ^ key;
return output;
}

Answer 1

I've 2 things to say:
1: The value of a string needs to be between 2 -> ""
string str_xored = 2*&.8"'*; //this is not a valid syntax = error
//valid
string str_xored = "2*&.8";
str += '"';
str += "'*";
2: In your case I would use iterators:
#include <iostream>
#include <string>
//please don't use "using namespace std;"
std::string encryptDecrypt(std::string toEncrypt) {
char key = 'K'; //Any char will work
std::string output = ""; //needs to be empty
for (auto i = toEncrypt.begin(); i != toEncrypt.end(); i++) {
output += *i ^ key; //*i holds the current character to see how
//an iterator works have a look at my link
}
return output;
}
int main() {
std::string str = encryptDecrypt("Hello...!");
std::cout << str << std::endl;
return 0;
}
Here have a look at the (string) iterator:
Link 1
Link 2
If you think iterators are too difficult then use your
for(int i = 0; i < str.size(); i++){
//CODE
}
for()-loop

Answer 2

You can't treat xored strings like normal strings!
value ^ same_value == 0
Treat them as normal containers instead.
Example:
#include <iostream>
#include <iterator>
#include <algorithm>
template<typename InputIterator, typename OutputIterator, typename Key>
void perform_xor(InputIterator begin, InputIterator end, OutputIterator out, Key const &key) {
std::transform(begin, end, out, [key](auto &&value) {
return value ^ key;
});
}
using namespace std;
int main() {
char test[] = "(2*&.8\"\'*";
perform_xor(begin(test), end(test), begin(test), '&');
copy(begin(test), end(test), ostream_iterator<int>(cout, " "));
cout << endl;
perform_xor(begin(test), end(test), begin(test), '&');
copy(begin(test), end(test), ostream_iterator<char>(cout));
return 0;
}
see: http://ideone.com/ryoNp5