title: What is the significance of single quotes vs double quotes in comparisons?
body: <p>This returns an error:</p>
  
  <pre><code>return (arg[0] == "-" &amp;&amp; arg[1] == "-") ? true : false;
  </code></pre>
  
  <p><em>error: ISO C++ forbids comparison between pointer and integer</em></p>
  
  <p>However, this does not:</p>
  
  <pre><code>return (arg[0] == '-' &amp;&amp; arg[1] == '-') ? true : false;
  </code></pre>
  
  <p>What is the difference between <code>'</code> and <code>"</code> ? </p>