title: Why is this javascript non-greedy regex matching nothing?
body: <p>Having the url and js regex below, I'd expect to catch the <code>f2fJsDFJ23</code>, but the non-greedy parts <code>.*?</code> and <code>\??</code> don't work as expected</p>
  
  <p>What's the reasoning?</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>let t = 'https://www.youtube.com/embed/f2fJsDFJ23?autoplay=1'
  let reg = /(?:embed\/)(.*?)(?:\??)/.exec(t)
  document.write(`6&gt;&gt;&gt; ${reg &amp;&amp; reg.join(' | ')} &lt;br/&gt;`)
  
  reg = /(?:embed\/)(.*)(?:\??)/.exec(t)
  document.write(`6&gt;&gt;&gt; ${reg &amp;&amp; reg.join(' | ')} &lt;br/&gt;`)
  
  reg = /(?:embed\/)(.*)(?:\?)/.exec(t)
  document.write(`6&gt;&gt;&gt; ${reg &amp;&amp; reg.join(' | ')} &lt;br/&gt;`)
  
  t = 'https://www.youtube.com/embed/f2fJsDFJ23'
  reg = /(?:embed\/)(.*?)(?:\??)/.exec(t)
  document.write(`6&gt;&gt;&gt; ${reg &amp;&amp; reg.join(' | ')} &lt;br/&gt;`)
  
  reg = /(?:embed\/)(.*)(?:\??)/.exec(t)
  document.write(`6&gt;&gt;&gt; ${reg &amp;&amp; reg.join(' | ')} &lt;br/&gt;`)
  
  reg = /(?:embed\/)(.*)(?:\?)/.exec(t)
  document.write(`6&gt;&gt;&gt; ${reg &amp;&amp; reg.join(' | ')} &lt;br/&gt;`)</code></pre>
  </div>
  </div>
  </p>