title: How do I include the string header?
body: <p>I'm trying to learn about <code>string</code>s, but different sources tell my to include different headers.</p>
  
  <p>Some say to use <code>&lt;string.h&gt;</code>, but others mention <code>"apstring.h"</code>.  I was able to do some basic stuff with <code>apstring</code>, but I've been told the other one is more powerful.  When I include <code>&lt;string.h&gt;</code> and try to declare some string variables, however, I get errors.  What is the proper usage?</p>