(PHP 5 >= 5.1.0)
SimpleXMLIterator::valid — Check whether the current element is valid
This method checks if the current element is valid after calls to SimpleXMLIterator::rewind() or SimpleXMLIterator::next().
此函数没有参数。
Returns TRUE if the current element is valid, otherwise FALSE
Example #1 Check whether the current element is valid
<?php
$xmlIterator = new SimpleXMLIterator('<books><book>SQL Basics</book></books>');
$xmlIterator->rewind(); // rewind to the first element
echo var_dump($xmlIterator->valid()); // bool(true)
$xmlIterator->next(); // advance to the next element
echo var_dump($xmlIterator->valid()); // bool(false) because there is only one element
?>