PHP

Syntax:

bool SimpleXMLIterator::valid (void)

Parameters:this function takes no parameters.Return Value:This function returns TRUE if the current item is valid, or FALSE if it fails.The following programs illustrate PHP`s SimpleXMLIterator::valid() function:Program 1:  
// Save the xml element to a variable $xml = < < < XML < organization > < name > GeeksforGeeks < / name > < address > Noida India < / address > < contact > < email > [email protected]< / email > < mobile > + 91-987654321 < / mobile > < / contact > < / organization > XML; $xmlIt = new SimpleXMLIterator ( $xml );  
// Use the rewind() function to rewind
// to the first element $xmlIt -> rewind ();  
// Show result var_dump ( $xmlIt -> valid());  
// Use the next() function to navigate
// next element $xmlIt -> next(); $xmlIt -> next(); $xmlIt -> next();  
// Show result var_dump ( $xmlIt -> valid());  
?> Exit:

bool (true ) bool (false)

Program 2:  
// Save the xml element to a variable $xml = < < < XML < organization > < name > GeeksforGeeks < / name > < address > Noida India < / address > < contact > < email > [email protected]< / email > < mobile > + 91-987654321 < / mobile > < / contact > < / organization > XML; $xmlIt = new SimpleXMLIterator ( $xml );  
// the loop starts from the first xml element and
// run when elements are invalid for ( $xmlIt -> rewind (); $xmlIt -> valid(); $xmlIt -> next()) {   var_dump ( $xmlIt -> key()); }  
?> Exit:

string (4 ) "name" string (7) "address" string (7) "contact"

Link: https://www.php.net/manual/en/simplexmliterator.valid.php