Using foreach over an object implementing ArrayAccess and Iterator

Question

Is there a way to iterate over an object's keys implementing ArrayAccess and Iterator interfaces? Array access works as a charm but I can't use foreach on those objects which would help me a lot. Is it possible? I have such code so far:

<?php
class IteratorTest implements ArrayAccess, Iterator {
  private $pointer = 0;

  public function offsetExists($index) {
    return isset($this->objects[$index]);
  }

  public function offsetGet($index) {
    return $this->objects[$index];
  }

  public function offsetSet($index, $newValue) {
    $this->objects[$index] = $newValue;
  }

  public function offsetUnset($index) {
    unset($this->objects[$index]);
  }

  public function key() {
    return $this->pointer;
  }

  public function current() {
    return $this->objects[$this -> pointer];
  }

  public function next() {
    $this->pointer++;
  }

  public function rewind() {
    $this->pointer = 0;
  }

  public function seek($position) {
    $this->pointer = $position;
  }

  public function valid() {
    return isset($this->objects[$this -> pointer]);
  }
}

$it = new IteratorTest();

$it['one'] = 1;
$it['two'] = 2;

foreach ($it as $k => $v) {
  echo "$k: $v\n";
}

// expected result:
// one: 1
// two: 2

Thanks for any help and hints.

DerSchinken · Accepted Answer · 2024-01-31 07:05:11Z

I use this to implement Iterator. Maybe you can adapt it to your code ;)

class ModelList implements Iterator {
    public  $list;

    private $index = 0;

    public  $nb;

    public  $nbTotal;

    public function __construct() {
        $this->list    = [];
        $this->nb      = 0;
        $this->nbTotal = 0;

        return $this;
    }

    /**
     * list navigation
     */
    public function rewind() {
        $this->index = 0;
    }

    public function current() {
        $k   = array_keys( $this->list );
        $var = $this->list[ $k[ $this->index ] ];

        return $var;
    }

    public function key() {
        $k   = array_keys( $this->list );
        $var = $k[ $this->index ];

        return $var;
    }

    public function next() {
        $k = array_keys( $this->list );
        if ( isset( $k[ ++$this->index ] ) ) {
            $var = $this->list[ $k[ $this->index ] ];

            return $var;
        } else {
            return false;
        }
    }

    public function valid() {
        $k   = array_keys( $this->list );
        $var = isset( $k[ $this->index ] );

        return $var;
    }
}

Community · Accepted Answer · 2017-05-23 12:22:17Z

2

while ($it->valid()) {
    echo $it->key().' '.$it->current();
    $it->next();
}

Would be my approach, however, this function looks iffy:

 public function next() {
    $this->pointer++;
 }

Incrementing 'one' isn't likely to give you 'two'. Try the code in the answers to this question to get the next array key:

$keys = array_keys($this->objects);
$position = array_search($this->key(), $keys);
if (isset($keys[$position + 1])) {
    $this->pointer = $keys[$position + 1];
} else {
    $this->pointer = false;
}

edited May 23, 2017 at 12:22

CommunityBot

11 silver badge

answered Apr 2, 2012 at 8:34

Matt Gibson

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1 Comment

hrwath Over a year ago

Thanks for the tips but I need these objects working using foreach because they are being passed as arguments to other functions I can't modify. I have modified it a bit and it seems to work: http://ideone.com/rZjim

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