Main Activity java file for math operations implementing addition and subtraction

MainActivity.java

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
    //Declaration of components (editext & textview) and global variables (string and double)
    EditText ed1, ed2;
    String value1, value2;
    Double val1, val2, total;
    TextView tvResult;

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

        //reference the components to the layout file
        ed1 = findViewById(R.id.ed1);
        ed2 = findViewById(R.id.ed2);
        tvResult = findViewById(R.id.tvResult);

//        //Get the text entered in the editext and save it in the string
//        value1 = ed1.getText().toString();
//        value2 = ed2.getText().toString();
//
//        //Convert the string to double
//        val1 = Double.parseDouble(value1);
//        val2 = Double.parseDouble(value2);
    }

    public void addition(View view) {
        value1 = ed1.getText().toString();
        value2 = ed2.getText().toString();

        //Convert the string to double
        val1 = Double.parseDouble(value1);
        val2 = Double.parseDouble(value2);

        //do the addition and display the results in the textview
        total = val1 + val2;
        // tvResult.setText(total.toString());
        String finalresult = String.valueOf(total);
        tvResult.setText(finalresult);
    }

    public void subtraction(View view) {
        value1 = ed1.getText().toString();
        value2 = ed2.getText().toString();

        //Convert the string to double
        val1 = Double.parseDouble(value1);
        val2 = Double.parseDouble(value2);

        //do the subtraction and display the results in the textview
        total = val1 - val2;
        //tvResult.setText(total.toString());
        String finalresult = String.valueOf(total);
        tvResult.setText(finalresult);
    }

    public void multiplication(View view){}
    public void division(View view){}
}