If you want something like `ArrayCallbackIterator` by Relakuyae https://www.php.net/manual/ru/class.arrayiterator.php#106231 , use function `iterator_apply`.
(PHP 5, PHP 7)
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。
ArrayIterator::STD_PROP_LISTProperties of the object have their normal functionality when accessed as list (var_dump, foreach, etc.).
ArrayIterator::ARRAY_AS_PROPS可以通过属性访问条目（读写都支持）。
If you want something like `ArrayCallbackIterator` by Relakuyae https://www.php.net/manual/ru/class.arrayiterator.php#106231 , use function `iterator_apply`.
<?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());
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"));
?>
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.
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
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";
/* Outputs something like */
Iterating over: 4 values
apple=yummy
orange=ah ya, nice
grape=wow, I love it!
plum=nah, not me
?>
Regards.