title: Assigning negative value to char
body: <p>Why does the following code print "?" ? 
  Also how can -1 be assigned to an <code>unsigned char</code>?</p>
  
  <pre><code>char test;
  unsigned char testu; //isn't it supposed to hold values in range 0 - 255?
  test = -1;
  testu = -1;
  cout&lt;&lt;"TEST CHAR = "&lt;&lt;test&lt;&lt;endl;
  cout&lt;&lt;"TESTU CHAR = "&lt;&lt;testu&lt;&lt;endl;
  </code></pre>