title: Change Truthy/Falsey value of Javascript Object
body: <p>Basically can I do the following...</p>
  
  <pre><code>var obj = {}:
  obj.falsey = true;
  if(obj){
     //code not executed
  }else{
     //code executed
  }
  </code></pre>
  
  <p>I could take advantage of the fact <code>!</code>,<code>+</code>,<code>~</code>...
  Call <code>valueOf/toString</code> and do the following, but I would like to avoid that.</p>
  
  <pre><code>var obj = {valueOf:function(){return 0}}:
  obj.falsey = true;
  if(!!obj){
     //code not executed
  }else{
     //code executed
  }
  </code></pre>
  
  <p>Why would I want to do this?  Because I'm curious :D</p>