Convert number in textview to int

Question

So, I am messing around with java/android programming and right now I am trying to make a really basic calculator. I am hung up on this issue though. This is the code I have r

Answer 1

TextView tv = (TextView)findviewbyID(R.id.textView);
String text = tv.getText().toString();
int n;
if(text.matches("\\d+")) //check if only digits. Could also be text.matches("[0-9]+")
{
   n = Integer.parseInt(text);
}
else
{
   System.out.println("not a valid number");
}