It says Null Pointer Exception: Attempt to invoke virtual method 'android.text.Editable android.widget.EditText.getText()' on a null object reference

Question

Here in method rooms it shows error " Null Pointer Exception: Attempt to invoke virtual method 'android.text.Editable android.widget.EditText.getText()' on a null object reference". I don't know what to do incase of strings, do help me

i get "Attempt to invoke virtual method 'android.text.Editable android.widget.EditText.getText()' on a null object reference" whenever i click on the button. help please

    CircleImageView circleImageView;
    ImageView imageView;
    private static final int PICK_Image=1;
    Button button;
 //   String title,description,email,phone_number,location,price,internet,parking;

    EditText a,b,c,d,e,f,g,h;

    private static final String ARG_PARAM1 = "param1";
    private static final String ARG_PARAM2 = "param2";


    private String mParam1;
    private String mParam2;

    public HouseOwner() {
        // Required empty public constructor
    }


    public static HouseOwner newInstance(String param1, String param2) {
        HouseOwner fragment = new HouseOwner();
        return fragment;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        getActivity(). `getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN);`




    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.fragment_house_owner, container, false);

    }

    @Override
    public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);

       

     /*   TextView textView = view.findViewById(R.id.search);
        textView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                startActivity(new Intent(startActivity();));*//*
            }
        });*/

        imageView = view.findViewById(R.id.pick);

        button = view.findViewById(R.id.done);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                rooms();
            }
        });

        CircleImageView circleImageView = view.findViewById(R.id.add);
        circleImageView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

                Intent intent = new Intent();
                intent.setType("image/*");
                intent.setAction(Intent.ACTION_GET_CONTENT);

                startActivityForResult(Intent.createChooser(intent,"Select"),PICK_Image);

            }
        });

    }

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data){
        super.onActivityResult(requestCode,resultCode, data);

        if (requestCode == 1){

            Uri uri = data.getData();
            imageView.setImageURI(uri);
        }
    }

    private void rooms(){

        **String title = a.getText().toString().trim();**  **The error starts here**
        String description = b.getText().toString().trim();
        String email = c.getText().toString().trim();

        String phone_number = d.getText().toString().trim();
        String location = e.getText().toString().trim();
        String price = f.getText().toString().trim();
        String internet = g.getText().toString().trim();
        String parking = h.getText().toString().trim();



        Log.d("response", "user: " + title);

        Log.d("response", "pass: " + description);

        if (title.isEmpty()){
            a.setError("Title is required");
            a.requestFocus();
            return;
        }

        if (description.isEmpty()){
            b.setError("Description is required");
            b.requestFocus();
            return;
        }

        if (email.isEmpty()){
            c.setError("Email is required");
            c.requestFocus();
            return;
        }

        if (phone_number.isEmpty()){
            d.setError("Number is required");
            d.requestFocus();
            return;
        }

        if (location.isEmpty()){
            e.setError("Location is required");
            e.requestFocus();
            return;
        }

        if (price.isEmpty()){
            f.setError("price is required");
            f.requestFocus();
            return;
        }

        if (internet.isEmpty()){
            g.setError("Internet is required");
            g.requestFocus();
            return;
        }

        if (parking.isEmpty()){
            h.setError("Parking is required");
            h.requestFocus();
            return;
        }



        Call<ResponseBody> call = RetrofitRooms
                .getInstance()
                .getroomPost()
                .rooms(title,description,email, phone_number,location,price,internet,parking);

        call.enqueue(new Callback<ResponseBody>() {
            @Override
            public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) {
                try {
                    //  String s = response.body().string();
                    if(response.body() != null ) {
                        String s = response.body().string();
                    }
                    Toast.makeText(getActivity(),"Success!",Toast.LENGTH_SHORT).show();
//                    Toast.makeText(second.this,s,Toast.LENGTH_LONG).show();
                } catch (IOException e) {
                    e.printStackTrace();
                }

            }

            @Override
            public void onFailure(Call<ResponseBody> call, Throwable t) {
                Toast.makeText(getActivity(),"Failed!",Toast.LENGTH_SHORT).show();
            }
        });
    }

}