php|architect's Guide to Web Scraping with PHP - Wind Business ...

SimpleXML Extension ” 117
Comparing N o d e s
T ocompare an element or attribute with a string value, you must first explicitly cast
it to a string. Otherwise, it will be treated as an object, which may causes type issues
including emitting errors.
DOM I n t e r o p e r a b i l i t y
With both the DOM and SimpleXML extensions being tree parsers, this allows for a
certain degree of interoperability between the two. This can be handy if you prefer
one o v e r the other when refactoring legacy code or if you have use cases for both
within a single application.
XPath
Like the DOM extension, SimpleXML also supports XPath. Rather than using a separate
class for it as the DOM does, the SimpleXMLElement class itself includes a method
for it. Where the query() and evaluate() methods of the DOMXPath class return a
DOMNodeList instance, the xpath method of SimpleXMLElement instead returns an enumerated
array of SimpleXMLElement instances that match the given XPath expression.