Close modal , toast, alert if android device back button clicked

hi guys i want when device back button clicked if modal is open close it

Any update on this question.

Check this:

You’d be calling -> this.yourModal.dismiss()

In your modal component constructor:

// register back button to close this modal
this.platform.registerBackButtonAction(() => {

In the page component where you call to open this modal:

// when modal is closed register back button to go back (default back button action)
let modalInstance = this.modalCtrl.create(ModalComponent);

modalInstance.onDidDismiss(() => {
   this.platform.registerBackButtonAction(() => {
    // if has history page go back  
    if (this.navCtrl.length() > 1) {