iterator(3) [php man page]

ITERATOR(3)								 1							       ITERATOR(3)

The Iterator interface

INTRODUCTION

	Interface for external iterators or objects that can be iterated themselves internally.

INTERFACE SYNOPSIS

       Iterator

       Iteratorextends
       Traversable

       Methods

       o abstractpublic mixed Iterator::current (void  )

       o abstractpublic scalar Iterator::key (void  )

       o abstractpublic void Iterator::next (void  )

       o abstractpublic void Iterator::rewind (void  )

       o abstractpublic boolean Iterator::valid (void  )

PREDEFINED ITERATORS

	PHP already provides a number of iterators for many day to day tasks. See SPL iterators for a list.

EXAMPLES

       Example #1

	      Basic usage

	       This example demonstrates in which order methods are called when using foreach with an iterator.

	      <?php
	      class myIterator implements Iterator {
		  private $position = 0;
		  private $array = array(
		      "firstelement",
		      "secondelement",
		      "lastelement",
		  );

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

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

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

		  function key() {
		      var_dump(__METHOD__);
		      return $this->position;
		  }

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

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

	      $it = new myIterator;

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

	      The above example will output something similar to:

	      string(18) "myIterator::rewind"
	      string(17) "myIterator::valid"
	      string(19) "myIterator::current"
	      string(15) "myIterator::key"
	      int(0)
	      string(12) "firstelement"

	      string(16) "myIterator::next"
	      string(17) "myIterator::valid"
	      string(19) "myIterator::current"
	      string(15) "myIterator::key"
	      int(1)
	      string(13) "secondelement"

	      string(16) "myIterator::next"
	      string(17) "myIterator::valid"
	      string(19) "myIterator::current"
	      string(15) "myIterator::key"
	      int(2)
	      string(11) "lastelement"

	      string(16) "myIterator::next"
	      string(17) "myIterator::valid"

PHP Documentation Group 													       ITERATOR(3)

SPLFIXEDARRAY(3)							 1							  SPLFIXEDARRAY(3)

The SplFixedArray class

INTRODUCTION

	The SplFixedArray class provides the main functionalities of array. The main differences between a SplFixedArray and a normal PHP array is
       that the SplFixedArray is of fixed length and allows only integers within the range as indexes. The advantage is that it  allows  a  faster
       array implementation.

CLASS SYNOPSIS

       SplFixedArray

       SplFixedArrayIteratorArrayAccessCountable

       Methods

       o public SplFixedArray::__construct ([int  $size])

       o public int SplFixedArray::count (void	)

       o public mixed SplFixedArray::current (void  )

       o publicstatic SplFixedArray SplFixedArray::fromArray (array  $array, [bool  $save_indexes = true])

       o public int SplFixedArray::getSize (void  )

       o public int SplFixedArray::key (void  )

       o public void SplFixedArray::next (void	)

       o public bool SplFixedArray::offsetExists (int  $index)

       o public mixed SplFixedArray::offsetGet (int  $index)

       o public void SplFixedArray::offsetSet (int  $index, mixed  $newval)

       o public void SplFixedArray::offsetUnset (int  $index)

       o public void SplFixedArray::rewind (void  )

       o public int SplFixedArray::setSize (int  $size)

       o public array SplFixedArray::toArray (void  )

       o public bool SplFixedArray::valid (void  )

       o public void SplFixedArray::__wakeup (void  )

EXAMPLES

       Example #1

	      SplFixedArray usage example

	      <?php
	      // Initialize the array with a fixed length
	      $array = new SplFixedArray(5);

	      $array[1] = 2;
	      $array[4] = "foo";

	      var_dump($array[0]); // NULL
	      var_dump($array[1]); // int(2)

	      var_dump($array["4"]); // string(3) "foo"

	      // Increase the size of the array to 10
	      $array->setSize(10);

	      $array[9] = "asdf";

	      // Shrink the array to a size of 2
	      $array->setSize(2);

	      // The following lines throw a RuntimeException: Index invalid or out of range
	      try {
		  var_dump($array["non-numeric"]);
	      } catch(RuntimeException $re) {
		  echo "RuntimeException: ".$re->getMessage()."
";
	      }

	      try {
		  var_dump($array[-1]);
	      } catch(RuntimeException $re) {
		  echo "RuntimeException: ".$re->getMessage()."
";
	      }

	      try {
		  var_dump($array[5]);
	      } catch(RuntimeException $re) {
		  echo "RuntimeException: ".$re->getMessage()."
";
	      }
	      ?>

	      The above example will output:

	      NULL
	      int(2)
	      string(3) "foo"
	      RuntimeException: Index invalid or out of range
	      RuntimeException: Index invalid or out of range
	      RuntimeException: Index invalid or out of range

PHP Documentation Group 													  SPLFIXEDARRAY(3)