title: If double a=0.0, can I compare a*b==0 directly?
body: <p>I know double should not be compared by == operator directly, but how about if I define an initial value as 0.0?eg:</p>
  
  <pre><code>double a=0.0;
  double b=
  .
  .
  .
  </code></pre>
  
  <p>If a is not modified, does a*b==0 always true?</p>