Iterators
PHP Manual

The CallbackFilterIterator class

Introduction

Class synopsis

CallbackFilterIterator
extends FilterIterator
/* Methods */
public CallbackFilterIterator::__construct(Iterator $iterator, callable $callback)
public bool CallbackFilterIterator::accept()
/* Inherited methods */
public bool accept()
public mixed current()
public mixed key()
public void next()
public void rewind()
public bool valid()
public mixed IteratorIterator::current()
public Iteratornull IteratorIterator::getInnerIterator()
public mixed IteratorIterator::key()
public void IteratorIterator::next()
public void IteratorIterator::rewind()
public bool IteratorIterator::valid()

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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