Iterate in reverse through an array with PHP - SPL solution?

Question

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)         


        

Answer 1

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);
    }
}