title: join array of objects by using one property
body: <p>I've got an array of objects with a few properties, such as 'value' and 'label'.</p>
  
  <p><code>array.join(' ')</code> of course gives me "[object] [object]", but instead I need to get a string of the 'value' properties of all objects, separated by a space.</p>
  
  <p>What is the shortest way to do this, and is this possible without writing a for loop?</p>