title: What does a tilde do when it precedes an expression?
body: <pre><code>var attr = ~'input,textarea'.indexOf( target.tagName.toLowerCase() )
             ? 'value'
             : 'innerHTML'
  </code></pre>
  
  <p>I saw it in an answer, and I've never seen it before.</p>
  
  <p>What does it mean?</p>