PHP 5.5+: Array vs Generator

array.php

<?php

function xrange($start, $end)
{
    $array = [];

    for ($i = $start; $i <= $end; $i++) {
        $array[] = $i;
    }

    return $array;
}

$max = isset($argv[1]) ? (int) $argv[1] : 1000000;
$items = xrange(1, $max);

echo "1: " . memory_get_usage() . "\n";

foreach ($items as $val) {

}

echo "2: " . memory_get_usage() . "\n";

generator.php

<?php

function xrange($start, $end)
{
    for ($i = $start; $i <= $end; $i++) {
        yield $i;
    }
}

$max = isset($argv[1]) ? (int) $argv[1] : 1000000;
$items = xrange(1, $max);

echo "1: " . memory_get_usage() . "\n";

foreach ($items as $val) {

}

echo "2: " . memory_get_usage() . "\n";