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
$value
)$array = array()
[, int $flags = 0
]] )$index
)$index
)$index
, string $newval
)$index
)$position
)$flags
)$cmp_function
)$cmp_function
)$serialized
)Table of Contents
- 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.