private void ambil_data_soal()
    {
        String[] ref ={"soal_0" , "soal_1" , "soal_2" , "soal_3" , "soal_4" , "soal_5" , "soal_6" , "soal_7" , "soal_8" , "soal_9"  , "soal_10"  , "soal_11"};

        for(i = 0 ; i < 1 ; i++)
        {
            DatabaseReference root3 = FirebaseDatabase.getInstance().getReference().child("catatan_soal").child(ref[i]);
            root3.addListenerForSingleValueEvent(new ValueEventListener() {
                @Override
                public void onDataChange(DataSnapshot dataSnapshot) {
                    data_soal[i] = dataSnapshot.getValue(String.class);


                }

                @Override
                public void onCancelled(DatabaseError databaseError) {

                }
            });


        }





    }