javascript for-in loop
<p>As the defination says for-in loop is used to loop through the properties of an object ,than why is it looping the element of an array?</p>

<pre><code>var arr = ['a','b','c'], indexes = [];

 Array.prototype.each = function() {/*blah*/};

 for (var index in arr) {
  indexes.push(index);
}
indexes; //["0", "1", "2", "each"]
</code></pre>

<p>why are 0,1,2 enumerated?They are not the properties </p>
