PHP | AppendIterator valid() Function

The AppendIterator::valid() function is an inbuilt function in PHP which is used to check the validity of the current element. Syntax:

bool AppendIterator::valid( void )

Parameters: This function does not accept any parameters. Return Value: This function returns TRUE if the current iteration is valid and FALSE otherwise. Below programs illustrate the AppendIterator::valid() function in PHP: Program 1: php

<?php
 
// Declare an ArrayIterator
$arr = new ArrayIterator(array('G', 'e', 'e', 'k', 's'));
 
// Create a new AppendIterator
$itr = new AppendIterator;
$itr->append($arr);
 
// Check the validity and display
// the result
while($itr->valid()) {
    echo $itr->current();
    $itr->next();
}
 
?>

Program 2: php

<?php
  
// Declare an ArrayIterator
$arr1 = new ArrayIterator(array("Geeks", "for", "Geeks"));
$arr2 = new ArrayIterator(array("Computer", "Science", "Portal"));
 
// Create a new AppendIterator
$itr = new AppendIterator;
$itr->append($arr1);
$itr->append($arr2);
 
// Using rewind function 
$itr->rewind(); 
 
// Check the validity and display the result
while($itr->valid()) { 
    var_dump($itr->current()); 
       
    // Moving to next element 
    $itr->next(); 
} 
  
?>

Reference: https://www.php.net/manual/en/appenditerator.valid.php