Intent로 Activity 간 데이터 교환MainActivitypublic class MainActivity extends AppCompatActivity implements View.OnClickListener{ @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); Button btn2 = findViewById(R.id.button2); btn2.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View vie..