SimpleXMLIterator::valid()
(PHP 5, PHP 7)
Check whether the current element is valid
说明
public SimpleXMLIterator::valid(void): bool
This method checks if the current element is valid after calls to SimpleXMLIterator::rewind() or SimpleXMLIterator::next().
参数
此函数没有参数。
返回值
Returns TRUE
if the current element is valid, otherwise FALSE
范例
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 ?>