title: Empty array with length different from zero. Can you explain me this?
body: <pre><code>var myNumb = 5;
  var myArr = Array(myNumb);
  console.log(myArr.length); // 5
  console.log(myArr[0]) // undefined, as well as for myArr[1] myArr[2] myArr[3] myArr[4]
  </code></pre>
  
  <p>These lines create an array <code>myArray</code> that has a length of 5, but it's also said "an empty array", in fact <code>myArr[0]</code> is <code>undefined</code>, for example.</p>
  
  <p>I can't understand how is possible to have an empty array with a length different from zero. If the array has not items, how can it have a length different from zero?</p>