Android Studio Main1

package com.example.activitylifecycle;

import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;

import android.app.Dialog;
import android.content.Intent;
import android.os.Bundle;
import android.text.TextUtils;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    TextView _regis;
    Button _btnlogin;
    EditText _txEm, _txPas;
    String _tempMail, _tempPass;
    int reqCode = 99;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        _regis = findViewById(R.id.regis_now);
        _btnlogin = findViewById(R.id.btn_login);
        _txEm = findViewById(R.id.user);
        _txPas = findViewById(R.id.pass);

        _regis.setOnClickListener(this);

        _btnlogin.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String mail = _txEm.getText().toString();
                String pas = _txPas.getText().toString();
//                if (_tempMail.equals(mail) && _tempPass.equals(pas)) {
//                    Intent mrhead = new Intent(MainActivity.this, MainActivity3.class);
//                    startActivity(mrhead);
//                } else
//                if (TextUtils.isEmpty(mail) && TextUtils.isEmpty(pas)) {
//                    Toast.makeText(MainActivity.this, "Tidak boleh kosong", Toast.LENGTH_SHORT).show();
//                }
                if (_txEm.length() == 0) {
                    _txEm.setError("Input Email");
                }
                else if (_txPas.length() == 0) {
                    _txPas.setError("Input Password");
                }
                else {
                    Toast.makeText(MainActivity.this, "Silahkan Registrasi", Toast.LENGTH_SHORT).show();
                }

                if (v.getId() == _btnlogin.getId()) {
                    if (!_tempMail.equals(mail) && _tempPass.equals(pas)) {
                        Toast.makeText(MainActivity.this, "Email Salah", Toast.LENGTH_SHORT).show();
                    } else if (_tempMail.equals(mail) && !_tempPass.equals(pas)) {
                        Toast.makeText(MainActivity.this, "Password Salah", Toast.LENGTH_SHORT).show();
                    } else if (_tempMail.equals(mail) && _tempPass.equals(pas)) {
                        Intent mrhead = new Intent(MainActivity.this, MainActivity3.class);
                        startActivity(mrhead);
                    }
                }
            }
        });
    }

    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        if (requestCode == reqCode) {
            if (resultCode == RESULT_OK) {
                _tempMail = data.getStringExtra("email");
                _tempPass = data.getStringExtra("pass");
                _txEm.setText(_tempMail);
            }
        }
    }

    @Override
    public void onClick(View v) {
        if (v.getId() == _regis.getId()) {
            Intent reg = new Intent(this, MainActivity2.class);
            reg.putExtra("asal", 99);
            this.startActivityForResult(reg, reqCode);
//            startActivity(reg);
        }
    }
}