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Bug #30972 Casting an empty single node SimpleXML object to boolean returns false
Submitted: 2004-12-03 05:47 UTC Modified: 2006-03-30 04:29 UTC
From: dtorop932 at gmail dot com Assigned:
Status: Closed Package: SimpleXML related
PHP Version: 5CVS-2004-12-03 (dev) OS: GNU/Linux 2.4.27
Private report: No CVE-ID: None
 [2004-12-03 05:47 UTC] dtorop932 at gmail dot com
According to it seems that in PHP 5 all objects should return TRUE when cast to boolean.  But if one creates a SimpleXML object from the string '<goodxml/>', then casts it to boolean, the result is FALSE.

As a comparison, running DOMDocument::loadxml() on "<goodxml/>" and casting the result to boolean returns TRUE.

This is important if one is doing what seems to be a quick test for failure of SimpleXML parsing, e.g. the following doesn't work as expected:

if (!simplexml_load_string($anyxml)) {
  return FALSE;  // this always executes, even for good XML

Reproduce code:
foreach (array('badxml', '<goodxml/>', '<goodxml>CONTENT</goodxml>') as $xml) {
  $dom = @simplexml_load_string($xml);
  print "\n\$dom from '$xml'\n";
  print '  ((boolean) $dom) = '; var_dump((boolean) $dom);

Expected result:

$dom from 'badxml'
  ((boolean) $dom) = bool(false)

$dom from '<goodxml/>'
  ((boolean) $dom) = bool(true)

$dom from '<goodxml>CONTENT</goodxml>'
  ((boolean) $dom) = bool(true)

Actual result:

$dom from 'badxml'
  ((boolean) $dom) = bool(false)

$dom from '<goodxml/>'
  ((boolean) $dom) = bool(false)

$dom from '<goodxml>CONTENT</goodxml>'
  ((boolean) $dom) = bool(true)


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 [2004-12-04 12:40 UTC]
Thank you for taking the time to write to us, but this is not
a bug. Please double-check the documentation available at and the instructions on how to report
a bug at

Use ===, !== or is_null
 [2006-03-30 04:29 UTC]
This bug has been fixed in CVS.

Snapshots of the sources are packaged every three hours; this change
will be in the next snapshot. You can grab the snapshot at
Thank you for the report, and for helping us make PHP better.

SimpleXML has its own cast handler which casts objects from empty tags to false
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