The ArrayIterator class

(PHP 5)

简介

这个迭代器允许在遍历数组和对象时删除和更新值与键

当你想多次遍历相同数组时你需要实例化ArrayObject，然后让这个实例创建一个ArrayIteratror实例当你想遍历相同数组时多次你需要实例ArrayObject并且让这个实例创建一个ArrayIteratror实例，然后使用foreach或者手动调用getIterator()方法

类摘要

ArrayIterator implements ArrayAccess , SeekableIterator , Countable , Serializable {

public void append ( mixed $value )

public void asort ( void )

public __construct ([ mixed $array = array() [, int $flags = 0 ]] )

public int count ( void )

public mixed current ( void )

public array getArrayCopy ( void )

public void getFlags ( void )

public mixed key ( void )

public void ksort ( void )

public void natcasesort ( void )

public void natsort ( void )

public void next ( void )

public void offsetExists ( string $index )

public mixed offsetGet ( string $index )

public void offsetSet ( string $index , string $newval )

public void offsetUnset ( string $index )

public void rewind ( void )

public void seek ( int $position )

public string serialize ( void )

public void setFlags ( string $flags )

public void uasort ( string $cmp_function )

public void uksort ( string $cmp_function )

public string unserialize ( string $serialized )

public bool valid ( void )

}

ArrayIterator::append — Append an element
ArrayIterator::asort — Sort array by values
ArrayIterator::__construct — Construct an ArrayIterator
ArrayIterator::count — Count elements
ArrayIterator::current — Return current array entry
ArrayIterator::getArrayCopy — Get array copy
ArrayIterator::getFlags — Get flags
ArrayIterator::key — Return current array key
ArrayIterator::ksort — Sort array by keys
ArrayIterator::natcasesort — Sort an array naturally, case insensitive
ArrayIterator::natsort — Sort an array naturally
ArrayIterator::next — Move to next entry
ArrayIterator::offsetExists — Check if offset exists
ArrayIterator::offsetGet — Get value for an offset
ArrayIterator::offsetSet — Set value for an offset
ArrayIterator::offsetUnset — Unset value for an offset
ArrayIterator::rewind — Rewind array back to the start
ArrayIterator::seek — Seek to position
ArrayIterator::serialize — Serialize
ArrayIterator::setFlags — Set behaviour flags
ArrayIterator::uasort — User defined sort
ArrayIterator::uksort — User defined sort
ArrayIterator::unserialize — Unserialize
ArrayIterator::valid — Check whether array contains more entries

用户评论:

[#1] daniel dot rutkoski at gmail dot com [2015-09-25 02:28:30]

<?php
class PrintArray
{
    private $code = null;

    function __construct ($val)
    {
        $this->code = $val;
        $this->_print();
    }

    private function arrayIterator($val, $grau)
    {
        $grau++;
        $arr = new \ArrayIterator($val);
        while ($arr->valid())
        {
            if(is_array($arr->current()))
            {
                $this->arrayIterator($arr->current(), $grau);
            }
            else
            {
                $this->code .= str_repeat(" ", (4 * $grau)) . $arr->key() . " : " . $arr->current() . PHP_EOL;
            }
            $arr->next();
        }
    }

    private function _print()
    {
        if (is_array($this->code))
        {
            $arr = new \ArrayIterator($this->code);
            $this->code = 'array(' . PHP_EOL;
            while ($arr->valid())
            {
                if(is_array($arr->current()))
                {
                    $this->arrayIterator($arr->current(), 0);
                }
                else
                {
                    $this->code .= $arr->key() . " : " . $arr->current() . "\n";
                }
                $arr->next();
            }
            $this->code .= ')';
        }
        return $this;
    }

    public function getVal ()
    {
        return $this->code;
    }
}

$arr = array(
    array(
        'ok' => 1, array(9,7,5,9,'a','b'=>array(1,2)),
        'error' => 2, array('h','u','o')
    )
    , 'array'
);
$pArray = new PrintArray($arr);
var_dump($pArray->getVal());

[#2] Relakuyae [2011-10-19 17:23:33]

Need a callback on an iterated value, but don't have PHP 5.4+? This makes is stupid easy:

<?php class ArrayCallbackIterator extends ArrayIterator { private $callback; public function __construct($value, $callback) { parent::__construct($value); $this->callback = $callback; } public function current() { $value = parent::current(); return call_user_func($this->callback, $value); } } ?>

You can use it pretty much exactly as the Array Iterator:

<?php $iterator1 = new ArrayCallbackIterator($valueList, "callback_function"); $iterator2 = new ArrayCallbackIterator($valueList, array($object, "callback_class_method")); ?>

[#3] foobuilder at gmail dot com [2010-12-09 11:01:25]

Unsetting all keys of an ArrayItem within foreach will always leave the second key:

<?php $items = new ArrayObject(range(0, 9)); while (list($k, $v) = each($items)) { unset($items[$k]); } print_r($items); // ArrayIterator Object // ( // [storage:ArrayIterator:private] => Array // ( // [1] => 1 // ) // ) ?>

I'm not sure if this is a bug as unsetting keys within foreach is usually a bad idea to begin with (use while instead), but it's something to be aware of.

[#4] Sean Burlington [2009-05-26 05:15:47]

and to iterate recursively use the (sparsely documented) RecursiveArrayIterator

<?php $fruits = array( "apple" => "yummy", "orange" => "ah ya, nice", "grape" => "wow, I love it!", "plum" => "nah, not me" ); $veg = array("potato" => "chips", "carrot" => "soup"); $grocery = array($fruits, $veg); $obj = new ArrayObject( $grocery ); $it = new RecursiveIteratorIterator( new RecursiveArrayIterator($grocery)); foreach ($it as $key=>$val) echo $key.":".$val."\n"; ?>

Output
--------
apple:yummy
orange:ah ya, nice
grape:wow, I love it!
plum:nah, not me
potato:chips
carrot:soup

[#5] Venelin Vulkov [2008-11-11 03:44:02]

Another fine Iterator from php . You can use it especially when you have to iterate over objects

<?php $fruits = array( "apple" => "yummy", "orange" => "ah ya, nice", "grape" => "wow, I love it!", "plum" => "nah, not me" ); $obj = new ArrayObject( $fruits ); $it = $obj->getIterator(); // How many items are we iterating over? echo "Iterating over: " . $obj->count() . " values\n"; // Iterate over the values in the ArrayObject: while( $it->valid() ) { echo $it->key() . "=" . $it->current() . "\n"; $it->next(); } // The good thing here is that it can be iterated with foreach loop foreach ($it as $key=>$val) echo $key.":".$val."\n"; Iterating over: 4 values apple=yummy orange=ah ya, nice grape=wow, I love it! plum=nah, not me ?>

Regards.

The ArrayIterator class

简介

类摘要

Table of Contents

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