title: Short-hand to add many key/value pairs to an existing JavaScript object?
body: <p>If I have an existing POJO and want to add some key/value pairs to it, I normally do it like so:</p>
  
  <pre><code>var existingObject = {
      firstValue: 'hello'
  };
  
  /* some time later... */
  
  existingObject.secondValue = 'world';
  existingObject.thirdValue = 'new value';
  existingObject.fourthValue = 'another value';
  existingObject.fifthValue = 'another value';
  existingObject.sixthValue = 'another value';
  existingObject.seventhValue = 'another value';
  existingObject.eighthValue = 'another value';
  existingObject.adInfinitum = 'again and again...';
  </code></pre>
  
  <p>But I wonder if there is a more efficient way than this longhanded approach? Note however, that I am looking for alternatives to creating a temp object and calling <code>extend</code>. </p>
  
  <p>Also, simply storing the object in a smaller variable (like <code>var a = existingObject;</code> and using <code>a.newValue = 'something'</code>)  isn't a solution I am looking for.</p>
  
  <p>Is there a way to do this?</p>