preg_replace vs str_replace

most_recent.php

<?php

$channels = array(
    "UCgpy7yxv_7JbR26McdS1uQA",
    "UCrHZJ6fddxeK2wwPIh5-O4Q",
    "UCYUI-AaHyYslLLWAss4EiAA",
);

$res = 5;
$key = 'YOUR_KEY_HERE';
$results = new ArrayObject();

$criteria = sprintf(
    '&maxResults=%s&order=date&key=%s&fields=items(id)',
    $res, $key
);

$baseUrl = 'https://www.googleapis.com/youtube/v3/search?part=snippet';

foreach ($channels as $user) {
    $endpoint = sprintf(
        '%s&channelId=%s%s',
        $baseUrl,
        $user,
        $criteria
    );
    $scraped = file_get_contents($endpoint);
    $decoded = json_decode($scraped, true);

    $results->append($decoded);

    /*
     * sfat: fa un sleep aici sa nu iei mereu imediat urmatorul element,
     *       e posibil sa te baneze la un moment dat
     */
}

foreach ($results as $id) {
    foreach ($id['items'] as $item) {
        foreach ($item as $clip) {
            echo $clip['videoId'] . PHP_EOL;
        }
    }
}

preg_vs_str_replace.php

<?php

$original = 'prepend/youtube#video/postpend';
$counter = 1000;

$start = microtime(true);

for ($walk = 0; $walk < $counter; $walk++) {
    $computed = preg_replace('/youtube#video/', '', $original);
}

$end = microtime(true);

echo sprintf('preg_replace took %f', $end - $start) . PHP_EOL;

$start = microtime(true);

for ($walk = 0; $walk < $counter; $walk++) {
    $computed = str_replace('/youtube#video/', '', $original);
}

$end = microtime(true);

echo sprintf('str_replace took %f', $end - $start) . PHP_EOL;