RegEx to Extract Video ID from YouTube URLs

The regular expression will extract the video ID from any YouTube URL and it works with shortened URLs ( and embed URLs ( as well.

function extractVideoID(url){
    var regExp = /^.*((\/)|(v\/)|(\/u\/\w\/)|(embed\/)|(watch\?))\??v?=?([^#\&\?]*).*/;
    var match = url.match(regExp);
    if ( match && match[7].length == 11 ){
        return match[7];
        alert("Could not extract video ID.");

Another alternative that will extract the video ID as well as the playlist ID from YouTube URLS:

    var id = url.match("v=([a-zA-Z0-9\_\-]+)&?")[1];
    var list = url.match("list=([a-zA-Z0-9\-\_]+)&?");
    list = list ? list[1] : "";