Question

As far as I know, I put in the correct try catch statements to stop the NumberFormatException…the NullPointerException may be coming from this:

TextView tvfin = null;
tvfin.setText(fin+"");
tvfin = (TextView)findViewById(R.id.tvfinalgrade);

Those three lines are going to be in an OnClickListener but I haven’t created it yet, I’m not sure if that could cause a problem?
Any help is much appreciated!

package wilson.GC;

import android.app.Activity;
import android.os.Bundle;
import android.widget.EditText;
import android.widget.TextView;

public class GFActivity extends Activity {

 @Override
    public void onCreate(Bundle savedInstanceState) {          

        super.onCreate(savedInstanceState);    
        setContentView(R.layout.getfinal);

        double q1, q2, ex, fin;
         EditText etq1, etq2, eteg;
         etq1 = (EditText)findViewById(R.id.editText1);
            try{
                q1 = Double.parseDouble(etq1.getText().toString());
            } catch (NumberFormatException e) {
                q1=0;
            }
         etq2 = (EditText)findViewById(R.id.editText2);
            try{
                q2 = Double.parseDouble(etq2.getText().toString());
            } catch (NumberFormatException e){
                q2 = 0;
            }
         eteg = (EditText)findViewById(R.id.editText3);
         try{
             ex = Double.parseDouble(eteg.getText().toString());
         } catch (NumberFormatException e){
             ex = 0;
         }
        fin = 0.4*q1+0.4*q2+0.2*ex;
            if(fin == (int)fin){
                System.out.println((int)fin);
            }
            else{
                fin = 0.01*((int)(fin*100));
                System.out.println(fin);
            } 
        TextView tvfin = null;
        tvfin.setText(fin+"");
        tvfin = (TextView)findViewById(R.id.tvfinalgrade);

    }
}

Answer 1

Try setting tvfin before setting its text:

TextView tvfin = (TextView)findViewById(R.id.tvfinalgrade);
tvfin.setText(fin+"");