title: Why _.map iteratee's arguments is (value, key) not (key, value)?
body: <p>According to the doc, </p>
  
  <blockquote>
    <p>If list is a JavaScript object, iteratee's arguments will be (value, key, list).</p>
  </blockquote>
  
  <p>I constantly have to check the doc to verify the order. Why is <code>value, key</code> not <code>key, value</code>?</p>
  
  <p><strong>[EDIT]</strong></p>
  
  <p>I guess I'm (always) confused because the for loop in CoffeeScript iterates on <code>key, value</code>:</p>
  
  <pre><code>yearsOld = max: 10, ida: 9, tim: 11
  
  ages = for child, age of yearsOld
    "#{child} is #{age}"
  </code></pre>