title: C - Convert char to int
body: <p>I know that to convert any given char to int, this code is possible [apart from atoi()]:</p>
  
  <pre><code>int i = '2' - '0';
  </code></pre>
  
  <p>but I never understood how it worked, what is significance of '0' and I don't seem to find any explanation on the net about that.</p>
  
  <p>Thanks in advance!!</p>