Iterators
PHP Manual

The CallbackFilterIterator class

(PHP 5 >= 5.4.0)

Introduction

Class synopsis

CallbackFilterIterator extends FilterIterator implements OuterIterator {
/* Methods */
public __construct ( Iterator $iterator , callable $callback )
public string accept ( void )
/* Inherited methods */
public abstract bool FilterIterator::accept ( void )
public FilterIterator::__construct ( Iterator $iterator )
public mixed FilterIterator::current ( void )
public Iterator FilterIterator::getInnerIterator ( void )
public mixed FilterIterator::key ( void )
public void FilterIterator::next ( void )
public void FilterIterator::rewind ( void )
public bool FilterIterator::valid ( void )
}

Examples

The callback should accept up to three arguments: the current item, the current key and the iterator, respectively.

Example #1 Available callback arguments

<?php

/**
 * Callback for CallbackFilterIterator
 *
 * @param $current   Current item's value
 * @param $key       Current item's key
 * @param $iterator  Iterator being filtered
 * @return boolean   TRUE to accept the current item, FALSE otherwise
 */
function my_callback($current, $key, $iterator) {
    // Your filtering code here
}

?>

Any callable may be used; such as a string containing a function name, an array for a method, or an anonymous function.

Example #2 Callback basic examples

<?php

$dir = new FilesystemIterator(__DIR__);

// Filter large files ( > 100MB)
function is_large_file($current) {
    return $current->isFile() && $current->getSize() > 104857600;
}
$large_files = new CallbackFilterIterator($dir, 'is_large_file');

// Filter directories
$files = new CallbackFilterIterator($dir, function ($current, $key, $iterator) {
    return $current->isDir() && ! $iterator->isDot();
});

?>

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Iterators
PHP Manual