title: .hasOwnProperty... and value?
body: <p>I ran across a small gotcha as an issue today with javascripts Object.hasOwnProperty.</p>
  
  <p>I have a form that is building out properties on an object. The issue occurred with a select box that was selected a value and was the reset back to the default value or essentially left blank.</p>
  
  <p>example: </p>
  
  <pre><code>var MemberSchema = {
    name: 'Name',
    country: 'Country'
    //ect...
  }
  
  function validateMember(member){
    for(var k in MemberSchema){
      if(!member.hasOwnProperty(k)){
         return false;
      }
    }
  return true
  }
  </code></pre>
  
  <p>The problem occurred by the form adding as soon as the select box was changed </p>
  
  <p><code>member.country = 'USA'</code></p>
  
  <p>But do to random user error occasionally the select box would be triggered back to </p>
  
  <p>--Select Country--</p>
  
  <p>which has an undefined value so the following occurred </p>
  
  <p><code>member.country = undefined</code></p>
  
  <p>Thus allowing the validateMember function to fail in detecting an actual complete member.</p>