Php-iterator interface

An interface for an external iterator or class that can iterate internally.

Interface Summary

Iterator extends Traversable {/    * method */    Abstract public mixed current (void) abstract public    scalar key (VO ID) abstract public    void Next (void),    abstract public void rewind (void),    abstract Public, Boolean valid (V OID)}

Pre-defined Iterators

PHP has provided some iterators for everyday tasks, such as SPL iterators.

Example

Example #1 Basic Usage

This example shows the sequence of calls to the Iterator method when using foreach.

<?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 "\ n"; }?>

The output of the above routines is similar to the following:

String "Myiterator::rewind" string (myiterator::valid) "Myiterator::current" string (15) " Myiterator::key "Int (0) string ()" Firstelement "string (+)" Myiterator::next "string (" Myiterator::valid "string ( "Myiterator::current" string ("Myiterator::key" int (1) "Secondelement" string () "Myiterator::next" String (2) "Myiterator::valid" string (11) "Myiterator::current" string ("Myiterator::key" Lastelement "string (myiterator::next)" string "Myiterator::valid"

Method List

iterator::current-returns the current element

iterator::key-returns the key of the current element

Iterator::next-move forward to the next element

Iterator::rewind-returns to the first element of an iterator

iterator::valid-Check if the current location is valid

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