title: XOR operator and char in C++
body: <p>Given the following code fragment in C++:</p>
  
  <pre><code>char a = 0x0a;
  char b = 0x80;
  char c = a ^ b;
  </code></pre>
  
  <p>what will happen behind the screen? When I use cout to output c, there was no output.
  Will the char a and char b be converted to binary format? what's the format of c?</p>