Iterator

(PHP 5 >= 5.0.0, PHP 7)

Examples:

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 "\n";
}
?>

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"

Links: