iterator.php

《PHP和MySQL Web开发》(第三版) Source

<?php
class ObjectIterator implements Iterator {

   private $obj;
   private $count;
   private $currentIndex;

   function __construct($obj) 
   {
     $this->obj = $obj;
     $this->count = count($this->obj->data);
   }
   function rewind() 
   {
     $this->currentIndex = 0;
   }
   function valid() 
   {
     return $this->currentIndex < $this->count;
   }
   function key() 
   {
     return $this->currentIndex;
   }
   function current() 
   {
     return $this->obj->data[$this->currentIndex];
   }
   function next() 
   {
     $this->currentIndex++;
   }
}

class Object implements IteratorAggregate 
{
  public $data = array();
  
  function __construct($in)
  {
    $this->data = $in;
  }

  function getIterator() 
  {
    return new ObjectIterator($this);
  }
} 

$myObject = new Object(array(2, 4, 6, 8, 10));

$myIterator = $myObj->getIterator();
for($myIterator->rewind(); $myIterator->valid(); $myIterator->next()) 
{
  $key = $myIterator->key();
  $value = $myIterator->current();
  echo "$key => $value <br />";
}

?>