PHP how to count xml elements in object returned by simplexml_load_file(),

I have inherited some PHP code (but I've little PHP experience) and can't find how to count some elements in the ob开发者_Go百科ject returned by simplexml_load_file()

The code is something like this

$xml = simplexml_load_file($feed);
for ($x=0; $x<6; $x++) {
   $title = $xml->channel[0]->item[$x]->title[0];
   echo "<li>" . $title . "</li>\n";
} 

It assumes there will be at least 6 <item> elements but sometimes there are fewer so I get warning messages in the output on my development system (though not on live).

How do I extract a count of <item> elements in $xml->channel[0]?

Here are several options, from my most to least favourite (of the ones provided).

• One option is to make use of the SimpleXMLIterator in conjunction with LimitIterator.

  $xml   = simplexml_load_file($feed, 'SimpleXMLIterator');
  $items = new LimitIterator($xml->channel->item, 0, 6);
  foreach ($items as $item) {
      echo "<li>{$item->title}</li>\n";
  }
  

• If that looks too scary, or not scary enough, then another is to throw XPath into the mix.

  $xml = simplexml_load_file($feed);
  $items = $xml->xpath('/rss/channel/item[position() <= 6]');
  foreach ($items as $item) {
      echo "<li>{$item->title}</li>\n";
  }
  

• Finally, with little change to your existing code, there is also.

  $xml = simplexml_load_file($feed);
  for ($x=0; $x<6; $x++) {
      // Break out of loop if no more items
      if (!isset($xml->channel[0]->item[$x])) {
          break;
      }
      $title = $xml->channel[0]->item[$x]->title[0];
      echo "<li>" . $title . "</li>\n";
  }
  

The easiest way is to use SimpleXMLElement::count() as:

$xml = simplexml_load_file($feed);
$num = $xml->channel[0]->count();
for ($x=0; $x<$num; $x++) {
   $title = $xml->channel[0]->item[$x]->title[0];
   echo "<li>" . $title . "</li>\n";
} 

Also note that the return of $xml->channel[0] is a SimpleXMLElement object. This class implements the Traversable interface so we can use it directly in a foreach loop:

$xml = simplexml_load_file($feed);
foreach($xml->channel[0] as $item {
   $title = $item->title[0];
   echo "<li>" . $title . "</li>\n";
} 

You get count by count($xml). I always do it like this:

 $xml = simplexml_load_file($feed);
 foreach($xml as $key => $one_row) {
        echo $one_row->some_xml_chield;
  }