title: Error in Eclipse: operator is undefined with EditText, double
body: <p>I am trying to make a simple tip calculator and have an EditText text field where you put in the amount of your total bill, then click on the percent button you want to calculate in tip (say, 10%) and then the onClickListener for that % button will calculate the tip and put the result into a different TextView field below itself.</p>
  
  <p>However, I know I had to change my EditText for my total bill from a string to a double, and included code for that, but I still get the error when I try to multiply the total bill times the tip of 10%. Why?</p>
  
  <p><strong>Here is my code:</strong></p>
  
  <pre><code>package com.example.nonitips;
  
  import android.app.Activity;
  import android.os.Bundle;
  import android.view.Menu;
  import android.view.MenuItem;
  import android.view.View;
  import android.widget.EditText;
  import android.widget.Toast;
  
  public class MainActivity extends Activity {
  
      public EditText totalBill;
      public double billWithTip;
  
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_main);
          totalBill = (EditText)findViewById(R.id.totalBill);
      }
  
      public void onTen (View v) {
          Toast.makeText(this, "Tipping at 10%", Toast.LENGTH_SHORT).show();
  
          totalBill.setOnClickListener(new View.OnClickListener() {
              @Override
              public void onClick(View v) {
                  double bill = Double.parseDouble(totalBill.getText().toString());
                  bill = (totalBill * 0.10) + totalBill; //Error on this line.
              }
          });
  
      }
  
      public void onFifteen (View v) {
          Toast.makeText(this, "Tipping at 15%", Toast.LENGTH_SHORT).show();
      }
  
      public void onTwenty (View v) {
          Toast.makeText(this, "Tipping at 20%", Toast.LENGTH_SHORT).show();
      }
  
      @Override
      public boolean onCreateOptionsMenu(Menu menu) {
  
          // Inflate the menu; this adds items to the action bar if it is present.
          getMenuInflater().inflate(R.menu.main, menu);
          return true;
      }
  
      @Override
      public boolean onOptionsItemSelected(MenuItem item) {
          // Handle action bar item clicks here. The action bar will
          // automatically handle clicks on the Home/Up button, so long
          // as you specify a parent activity in AndroidManifest.xml.
          int id = item.getItemId();
          if (id == R.id.action_settings) {
              return true;
          }
          return super.onOptionsItemSelected(item);
      }
  
  }
  </code></pre>