Calculator

import android.widget.*;

import android.view.*;

import android.view.View.OnClickListener;

public class MainActivity extends Activity {

EditText t1,t2,t3;

Button b1,b2,b3,b4,b5,b6;

            @Override

            protected void onCreate(Bundle savedInstanceState) {

                        super.onCreate(savedInstanceState);

                        setContentView(R.layout.activity_main);

                        t1=(EditText) findViewById(R.id.editText1);

                        t2=(EditText) findViewById(R.id.editText2);

                        t3=(EditText) findViewById(R.id.editText3);

                        b1=(Button) findViewById(R.id.button1);

                        b2=(Button) findViewById(R.id.button2);

                        b3=(Button) findViewById(R.id.button3);

                        b4=(Button) findViewById(R.id.button4);

                        b5=(Button) findViewById(R.id.button5);

                        b6=(Button) findViewById(R.id.button6);

                        b1.setOnClickListener(s1);

                        b2.setOnClickListener(s1);

                        b3.setOnClickListener(s1);

                        b4.setOnClickListener(s1);

                        b5.setOnClickListener(s1);

                        b6.setOnClickListener(s1);     }

public OnClickListener s1=new OnClickListener()

            {

               public void onClick(View v){

                           if(v==b1){

                           int x=Integer.parseInt(t1.getText().toString());

                           int y=Integer.parseInt(t2.getText().toString());

                           int z=x+y;

                           t3.setText(String.valueOf(z));

                          }

                           if(v==b2){

                                       int x=Integer.parseInt(t1.getText().toString());

                                       int y=Integer.parseInt(t2.getText().toString());

                                       int z=x-y;

                                       t3.setText(String.valueOf(z));

                                      }

                           if(v==b3){

                                       int x=Integer.parseInt(t1.getText().toString());

                                       int y=Integer.parseInt(t2.getText().toString());

                                       int z=x*y;

                                       t3.setText(String.valueOf(z));

                                      }

                           if(v==b4){

                                       int x=Integer.parseInt(t1.getText().toString());

                                       int y=Integer.parseInt(t2.getText().toString());

                                       int z=x/y;

                                       t3.setText(String.valueOf(z));

                                      }

                           if(v==b5){

                                       int x=Integer.parseInt(t1.getText().toString());

                                       int y=Integer.parseInt(t2.getText().toString());

                                       int z=x%y;

                                       t3.setText(String.valueOf(z));

                                      }

                           if(v==b6){

                                       t1.setText("");

                                       t2.setText("");

                                       t3.setText("");

                                      }

               }

             };

}