<?php
global $arr;
$i = 0;
$tmp = '';
while($i < 10000) {
	$tmp .= 'a';
	++$i;
}
$arr = array_fill(100000000000000000000000, 100, $tmp);
unset($i, $tmp);

$ts = microtime(true);
reset($arr);
do {
	$val = current($arr);
} while ( next($arr) !== false);

echo (microtime(true) - $ts) . PHP_EOL;