title: Android math operator
body: <p>I need calculate a thing. but my formula sentence has occur some problem.</p>
  
  <pre><code> TextView ticketP = (TextView)findViewById (R.id.ticketQ);
  
    ticketP.setText(oneSession.getTicketOder());
  
  String Ctotal = "";
  
  Ctotal = jsonObject.optString("price");
  
  
  
  
  String OneTotal = oneSession.getTicketOder() * Ctotal; // this part has occur the problem which is the operator *  . 
  </code></pre>