C++ Tutorial/Operators statements/XOR

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Demonstrate bitwise exclusive OR

#include <iostream>
using std::cout;
#include <iomanip>
using std::endl;
using std::setw;
void displayBits( unsigned );
int main()
{
   unsigned number1;
   unsigned number2;
   unsigned mask;
   unsigned setBits;
   number1 = 139;
   number2 = 199;
   cout << "\nThe result of combining the following\n";
   displayBits( number1 );
   displayBits( number2 );
   cout << "using the bitwise exclusive OR operator  is\n";
   displayBits( number1 ^ number2 );
   return 0;
}
//Quote from
//C++ How to Program (5th Edition) (How to Program) (Paperback)
//by Harvey & Paul) Deitel & Associates 
//Publisher: Prentice Hall; 5 edition (January 5, 2005)
//Language: English
//ISBN-10: 0131857576
//ISBN-13: 978-0131857575
void displayBits( unsigned value ) {
   const int SHIFT = 8 * sizeof( unsigned ) - 1;
   const unsigned MASK = 1 << SHIFT;
   cout << setw( 10 ) << value << " = ";
   for ( unsigned i = 1; i <= SHIFT + 1; i++ ) {
      cout << ( value & MASK ? "1" : "0" );
      value <<= 1;
      if ( i  8 == 0 )
         cout << " ";
   }
   cout << endl;
}
The result of combining the following
       139 = 00000000 00000000 00000000 10001011
       199 = 00000000 00000000 00000000 11000111
using the bitwise exclusive OR operator ^ is
        76 = 00000000 00000000 00000000 01001100

Use XOR to encode and ecode a message

#include <iostream> 
using namespace std; 
 
int main() 
{ 
  char msg[] = "This is a test"; 
  char key = 123; 
 
  cout << "Original message: " << msg << "\n"; 
 
  for(int i = 0 ; i < strlen(msg); i++)  
    msg[i] = msg[i] ^ key; 
 
  cout << "Encoded message: " << msg << "\n"; 
 
  for(int i = 0 ; i < strlen(msg); i++)  
    msg[i] = msg[i] ^ key; 
 
  cout << "Decoded message: " << msg << "\n"; 
 
  return 0; 
}
Original message: This is a test
Encoded message: /[[?[��
Decoded message: This is a test