title: Check if two integers have the same sign
body: <p>I'm searching for an efficient way to check if two numbers have the same sign.</p>
  
  <p>Basically I'm searching for a more elegant way than this:</p>
  
  <pre><code>var n1 = 1;
  var n2 = -1;
  
  ( (n1 &gt; 0 &amp;&amp; n2 &gt; 0) || (n1&lt;0 &amp;&amp; n2 &lt; 0) )? console.log("equal sign"):console.log("different sign");
  </code></pre>
  
  <p>A solution with bitwise operators would be fine too. </p>