title: How to extract alphanumeric word from string in dart?
body: <p>I have a string like as follows.</p>
  <pre class="lang-dart prettyprint-override"><code>var string = &quot;My id is 6aT7u. I used to play basketball and cricket.&quot;;
  </code></pre>
  <p>I have to extract the ID, i.e an alphanumeric word, using a regex. I have to extract <code>6aT7u</code> in this case.</p>
  <p>I tried <code>[a-zA-Z0-9]</code> but this doesn't work.</p>