title: For In Loop JSLint Error Message: Cannot read property "line" from undefined
body: <p>I'm running into a JSLint error "Cannot read property "line" from undefined", and cannot understand why that would be happening on this block of code:</p>
  
  <pre><code>function someThing(x){
      if(x &amp;&amp;typeof x==="object"){
          for(var i in x){
              //do stuff
          }
      }
  }
  </code></pre>
  
  <p>Any help would be appreciated.</p>