I need to show and hide back button in different pages/views. I took reference from Justin Noel:
I had problems with "hide-back-button", since it hides the menu and the back button. Somehow this.navCtrl.push played with the back button, in case you want the menu to be displayed using this.nav.setRoot(yourPage)
this.navCtrl.push
this.nav.setRoot(yourPage)