(PHP 5 >= 5.0.0, PHP 7)
Interface to create an external Iterator.
Example #1 Basic usage
<?php
class myData implements IteratorAggregate {
public $property1 = "Public property one";
public $property2 = "Public property two";
public $property3 = "Public property three";
public function __construct() {
$this->property4 = "last property";
}
public function getIterator() {
return new ArrayIterator($this);
}
}
$obj = new myData;
foreach($obj as $key => $value) {
var_dump($key, $value);
echo "\n";
}
?>
The above example will output something similar to:
string(9) "property1" string(19) "Public property one" string(9) "property2" string(19) "Public property two" string(9) "property3" string(21) "Public property three" string(9) "property4" string(13) "last property"
Note that, at least as of 5.3, you still aren't allowed to return a normal Array from getIterator().
In some places, the docs wrap the array into an ArrayObject and return that. DON'T DO IT. ArrayObject drops any empty-string keys on the floor when you iterate over it (again, at least as of 5.3).
Use ArrayIterator instead. I wouldn't be surprised if it didn't have its own set of wonderful bugs, but at the very least it works correctly when you use it with this method.
<?php
// IteratorAggregate
// Create indexed and associative arrays.
class myData implements IteratorAggregate {
private $array = [];
const TYPE_INDEXED = 1;
const TYPE_ASSOCIATIVE = 2;
public function __construct( array $data, $type = self::TYPE_INDEXED ) {
reset($data);
while( list($k, $v) = each($data) ) {
$type == self::TYPE_INDEXED ?
$this->array[] = $v :
$this->array[$k] = $v;
}
}
public function getIterator() {
return new ArrayIterator($this->array);
}
}
$obj = new myData(['one'=>'php','javascript','three'=>'c#','java',], /*TYPE 1 or 2*/ );
foreach($obj as $key => $value) {
var_dump($key, $value);
echo PHP_EOL;
}
// if TYPE == 1
#int(0)
#string(3) "php"
#int(1)
#string(10) "javascript"
#int(2)
#string(2) "c#"
#int(3)
#string(4) "java"
// if TYPE == 2
#string(3) "one"
#string(3) "php"
#int(0)
#string(10) "javascript"
#string(5) "three"
#string(2) "c#"
#int(1)
#string(4) "java"
?>
Good luck!
Example of the Iterator Pattern
<?php
namespace DesignPaterns;
class BookCollection implements \IteratorAggregate
{
private $a_titles = array();
public function getIterator()
{
return new BookIterator($this);
}
public function addTitle($string)
{
$this->a_titles[] = $string;
}
public function getTitle($key)
{
if (isset($this->a_titles[$key])){
return $this->a_titles[$key];
}
return null;
}
public function is_empty()
{
return empty($a_titles);
}
}
<?php
namespace DesignPaterns;
class BookIterator implements \Iterator
{
private $i_position = 0;
private $booksCollection;
public function __construct(BookCollection $booksCollection)
{
$this->booksCollection = $booksCollection;
}
public function current()
{
return $this->booksCollection->getTitle($this->i_position);
}
public function key()
{
return $this->i_position;
}
public function next()
{
$this->i_position++;
}
public function rewind()
{
$this->i_position = 0;
}
public function valid()
{
return !is_null($this->booksCollection->getTitle($this->i_position));
}
}
<?php require 'vendor/autoload.php';
use DesignPaterns\BookCollection;
$booksCollection = new BookCollection();
$booksCollection->addTitle('Design Patterns');
$booksCollection->addTitle('PHP7 is the best');
$booksCollection->addTitle('Laravel Rules');
$booksCollection->addTitle('DHH Rules');
foreach($booksCollection as $book){
var_dump($book);
}
/* === Output ===
* string(15) "Design Patterns"
* string(16) "PHP7 is the best"
* string(13) "Laravel Rules"
* string(9) "DHH Rules"
*/
