PHP 手册
迭代器

The CallbackFilterIterator class

(PHP 5 >= 5.4.0)

简介

类摘要

CallbackFilterIterator extends FilterIterator implements Iterator , Traversable , OuterIterator {
/* 方法 */
public __construct ( Iterator $iterator , callable $callback )
public string accept ( void )
/* 继承的方法 */
abstract bool FilterIterator::accept ( void )
mixed FilterIterator::current ( void )
mixed FilterIterator::key ( void )
void FilterIterator::next ( void )
void FilterIterator::rewind ( void )
bool FilterIterator::valid ( void )
}

范例

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();
});

?>

Table of Contents


迭代器
PHP 手册