[javascript] How to iterate a table rows with JQuery and access some cell values?

<table class="checkout itemsOverview">
    <tr class="item">
        <td>GR-10 Senderos</td>
        <td><span class="value">15.00</span> €</td>
        <td><input type="text" value="1" maxlength="2" class="quantity" /></td>
    </tr>
    <tr class="item">
        <td>GR-10 Senderos<br/>GR-66 Camino de la Hermandad<br/>GR 88 Senderos del   Jarama<br/>Camino del Cid</td>
        <td><span class="value">45.00</span> €</td>
        <td><input type="text" class="quantity"   value="1" maxlength="2"/></td>
    </tr>
</table>

I was trying with the next code to get the value and quantity of each item.

$("tr.item").each(function(i, tr) {
    var value = $(tr + " span.value").html();
    var quantity = $(tr + " input.quantity").val();
});

It is not working. Can anyone help me?

try this

var value = iterate('tr.item span.value');
var quantity = iterate('tr.item span.quantity');

function iterate(selector)
{
  var result = '';
  if ($(selector))
  {
    $(selector).each(function ()
    {
      if (result == '')
      {
        result = $(this).html();
      }
      else
      {
        result = result + "," + $(this).html();
      }
    });
  }
}

do this:

$("tr.item").each(function(i, tr) {
    var value = $("span.value", tr).text();
    var quantity = $("input.quantity", tr).val();
});