CODEWITHSUNDEEP
phparraysiterator
Alex
Alex

Reputation: 67698

Next Iterator method for associative Array

I want to use an associative array with the PHP iterator:

http://php.net/manual/en/class.iterator.php

is it possible?

I defined these methods:

  public function rewind(){    
    reset($this->_arr);
    $this->_position = key($this->_arr);
  }

  public function current(){    
    return $this->_arr[$this->_position];
  }

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

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

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

the problem is it doesn't iterate correctly. I only get one element.

I think it's because of the ++$this->_position code in the next() method which doesn't have any effect because _position is a string (key of the associative array).

so how can I go to the next element of this type of array?

Upvotes: 19

Views: 6072

Answers (5)

DarkMukke
DarkMukke

Reputation: 2489

I know this is an old question but it can be as simple as 

public function current()
{
    return $this->array[array_keys($this->array)[$this->position]];
}

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

public function key()
{
    return array_keys($this->array)[$this->position];
}

public function valid()
{
    return array_key_exists($this->position, array_keys($this->array)[$this->position]);
}

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

I know a similar answer was posted by @zerkms but imho that doesnt work if the object is already constructed and you have functionality that extends the array

Upvotes: 0

javadkh2
javadkh2

Reputation: 11

class MyItrator implements Iterator 
{
    private $_arr;

    public function __construct(array $arr) 
    {
        $this->_arr = $arr;
    }


    public function rewind()
    {
        reset($this->_arr);
    }

    public function current()
    {
        return current($this->_arr);
    }

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

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

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

Upvotes: 1

goat
goat

Reputation: 31823

function rewind() {
    reset($this->_arr);
}

function current() {
    return current($this->_arr);
}

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

function next() {
    next($this->_arr);
}

function valid() {
    return key($this->_arr) !== null;
}

Upvotes: 39

shadyyx
shadyyx

Reputation: 16055

Why not creating an ArrayObject from Your associative Array? Then You can getIterator() from this ArrayObject and call key(), next() etc on it as You want...

Some example:

$array = array('one' => 'ONE', 'two' => 'TWO', 'three' = 'THREE');
// create ArrayObject and get it's iterator
$ao = new ArrayObject($my_array);
$it = $ao->getIterator();
// looping
while($it->valid()) {
    echo "Under key {$it->key()} is value {$it->current()}";
    $it->next();
}

ArrayObject
ArrayIterator

Upvotes: 5

zerkms
zerkms

Reputation: 255005

http://ideone.com/Fxt0j

class myIterator implements Iterator {
    private $position = 0;
    private $keys;

    public function __construct(array $arr) {
        $this->array = $arr;
        $this->keys = array_keys($arr);
        $this->position = 0;
    }

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

    function current() {
        return $this->array[$this->key()];
    }

    function key() {
        return $this->keys[$this->position];
    }

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

    function valid() {
        return isset($this->keys[$this->position]);
    }
}

$it = new myIterator(array(
        'a' => "firstelement",
        'b' => "secondelement",
        'c' => "lastelement",
    ));

foreach($it as $key => $value) {
    var_dump($key, $value);
    echo "\n";
}

Upvotes: 2

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