lass="ion-display-none"></ion-back-button>
          </ion-buttons>
          <ion-title>Hidden</ion-title>
        </ion-toolbar>
      </ion-content>
    </ion-app>

    <script>
      var buttons = document.querySelectorAll('ion-back-button');

      for (var i = 0; i < buttons.length; i++) {
        buttons[i].addEventListener('click', (event) => onClick(event));
      }

      function onClick(ev) {
        console.log('clicked the button', ev.target.innerText);
      }
    </script>

    <style>
     