<?php

/**
* Example : rewind();
*/

$arr = new SplFixedArray(5);

$a = $arr->key(); //Zero'th index
var_dump($a);
echo "<br>";

$arr->next(); // Shift to first index
$a = $arr->key(); 
var_dump($a);
echo "<br>";

$arr->next(); // Shift to second index
$a = $arr->key();
var_dump($a);
echo "<br>";

$arr->next();  // Shift to third index
$a = $arr->key();
var_dump($a);
echo "<br>";
?>

The above example will output:

int(0) 
int(1) 
int(2) 
int(3)