title: shortening a URL string programmatically
body: <p>I have an <code>EditText</code> in my app which users can enter a youtube url.</p>
  
  <p>Example url is like following:</p>
  
  <pre><code>https://www.youtube.com/watch?v=gXrWv6zlg8s
  </code></pre>
  
  <p>When i grab the text and make it to a string, i only need the last chars like <strong>gXrWv6zlg8s</strong></p>
  
  <p>How can i shorten the string value to only this charset?</p>
  
  <pre><code>final EditText url = findViewById(R.id.url);
  b.setOnClickListener(new View.OnClickListener() {
          @Override
          public void onClick(View v) {
              String a;
              a = url.getText().toString().trim();}
  }
  </code></pre>
  
  <p>Thanks for advice.</p>