从XML结构获取指定参数的数组

Question

I have xml structure like this:

<categories>
   <category>
     <id>1</id>
     <name> category name </name>
          . 
          . 
          . 
   </category>
   <category>
     <id>2</id>
     <name> category name </name>
          . 
          . 
          . 
   </category> 
   <category>
     <id>3</id>
     <name> category name </name>
          .
          . 
          .       
   </category> 
   .
   . 
</categories>

And using PHP SimpleXML to convert xml to an array, but i have question: Is there some simple way to get one dimensional array only of category ids (like array(1, 2, 3, ... )) using some PHP function?

Thanks!

Answer 1

There is no built-in function to do that through SimpleXML directly. But it's not that hard to get the IDs with a foreach loop :

$categories = new SimpleXMLElement($my_xml);

foreach ($categories->category as $cat) {
  $arr[] = (string) $cat->id;
}