title: what does x-- or x++ do here?
body: <p>it is a silly Q for most of u - i know - but i one of the beginner here, and I can not understand why the output in here are  12 what does this (<code>x--</code>) do to the result ? </p>
  
  <pre><code>int x, y;
  x = 7;
  x-- ;
  y = x * 2;
  x = 3;
  </code></pre>