Youtube Scraper与Php

I'm a rookie programmer, trying to find his footing in PHP and i currently want to build a You-tube scraper.

This scraper would search You-tube for a key word, say "drop shipping", and return a list of links bearing that keyword in their title.

so far this is what i got:

require('simple_html_dom.php');

$html = file_get_html("https://www.youtube.com/results?search_query=dropshipping");


$videos = [];
$i = 1;
foreach($html ->find("div.yt-lockup yt-lockup-tile yt-lockup-video vve-check clearfix") as $video){

      if($i > 10){
        break;
      }

      $videoDetails = $video0->find("a.yt-uix-tile-link yt-ui-ellipsis yt-ui-ellipsis-2 yt-uix-servicelink spf-link");
      $videoTitle = $videoDetails ->title;
      $videoUrl = "http://youtube.com" . $videoDetails->href;
   echo $videoUrl;

     $videos[] = [

    "title" => $videoTitle,
    "link" => $videoUrl


      ];
      $i++;

}

     echo(sizeof($videos));

?>

This keeps outputting zero(0). Can't figure out why this is. I suspect that the tag link changes every now and then coz i echoed the html page and analyzed the link, some times you'd have the link class to be "yt-uix-servicelink" other times it would be "yt-uix-sessionlink"

Scraping is (naturally) forbidden by YouTube terms.

If you are interested in search itself, not implementing it by scraping specifically, you can look into using official API for it. Documentation for search:list has examples, including PHP one.