因为这似乎是我必须做的才能获得这种效果：
$arr = ['a'=>'first', 'b'=>'second', ...];
$iter = new ArrayIterator( $arr );
// Do a bunch of iterations...
$iter->next();
// ...
$new_iter = new ArrayIterator( $arr );
while( $new_iter->key() != $iter->key() ) {
$new_iter->next();
}
编辑：另外，为了清楚起见，我不应该用unset()修改基数组吗？我认为数组迭代器存储它自己的基数组副本，所以使用offsetUnset()似乎是不对的。
ArrayIterator没有实现tell()函数，但您可以模拟它，然后使用seek()转到您想要的位置。这里有一个扩展类可以做到这一点：
<?php
class ArrayIteratorTellable extends ArrayIterator {
private $position = 0;
public function next() {
$this->position++;
parent::next();
}
public function rewind() {
$this->position = 0;
parent::rewind();
}
public function seek($position) {
$this->position = $position;
parent::seek($position);
}
public function tell() {
return $this->position;
}
public function copy() {
$clone = clone $this;
$clone->seek($this->tell());
return $clone;
}
}
?>
使用：
<?php
$arr = array('a' => 'first', 'b' => 'second', 'c' => 'third', 'd' => 'fourth');
$iter = new ArrayIteratorTellable( $arr );
$iter->next();
$new_iter = new ArrayIteratorTellable( $arr );
var_dump($iter->current()); //string(6) "second"
var_dump($new_iter->current()); //string(6) "first"
$new_iter->seek($iter->tell()); //Set the pointer to the same as $iter
var_dump($new_iter->current()); //string(6) "second"
?>
演示
或者，您可以使用自定义copy()函数来克隆对象：
<?php
$arr = array('a' => 'first', 'b' => 'second', 'c' => 'third', 'd' => 'fourth');
$iter = new ArrayIteratorTellable( $arr );
$iter->next();
$new_iter = $iter->copy();
var_dump($iter->current()); //string(6) "second"
var_dump($new_iter->current()); //string(6) "second"
?>
DEMO
我想到的唯一解决方案是使用当前数组的副本
$arr = ['a'=>'first', 'b'=>'second'];
$iter = new ArrayIterator( $arr );
// Do a bunch of iterations...
$iter->next();
var_dump($iter->current());
// ...
$arr2 = $iter->getArrayCopy();
$new_iter = new ArrayIterator( $arr2 );
while( $new_iter->key() != $iter->key() ) {
var_dump($new_iter->current());
$new_iter->next();
}