Is there an SPL Reverse array iterator in PHP? And if not, what would be the best way to achieve it?
I could simply do
$array = array_reverse($array);
foreach($array as $currentElement) {}
or
for($i = count($array) - 1; $i >= 0; $i--)
{
}
But is there a more elegant way?
There is no ReverseArrayIterator
to do that. You can do
$reverted = new ArrayIterator(array_reverse($data));
or make that into your own custom iterator, e.g.
class ReverseArrayIterator extends ArrayIterator
{
public function __construct(array $array)
{
parent::__construct(array_reverse($array));
}
}
A slightly longer implementation that doesn't use array_reverse
but iterates the array via the standard array functions would be
class ReverseArrayIterator implements Iterator
{
private $array;
public function __construct(array $array)
{
$this->array = $array;
}
public function current()
{
return current($this->array);
}
public function next()
{
return prev($this->array);
}
public function key()
{
return key($this->array);
}
public function valid()
{
return key($this->array) !== null;
}
public function rewind()
{
end($this->array);
}
}