Example Alert on Android Studio

Simple Alert

Button toast, alertdialog, customalertdialog;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_massage_view);

    toast = findViewById(R.id.toast);
    alertdialog = findViewById(R.id.alertdialog);
    customalertdialog = findViewById(R.id.customalertdialog);

    toast.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {

        Toast.makeText(MassageView.this, "My Name is Cecep", Toast.LENGTH_LONG).show();
    }
});