Back button and menu issue


In the conference app I am not able to understand how the menu is enabled and back button is disabled in tabs page.
Also in tutorial how is menu disable as when I am doing in tutorial page
ionViewDidEnter() {
// the root left menu should be disabled on the tutorial page;
here still I am not able to see the menu.

Is there anything I am missic here

<ion-navbar> controls if the back button should be shown or not. The tabs page does not include the <ion-navbar> in the template hence the back button is not shown.
Tabs by default in ionic are designed to be parent containers, so you wont have back button in any tabs page.