Java Programming Tutorial - 23 - Compound Interest Program

class apples{
   public static void main(String[] args){
      double amount;
      double principal;
      double rate = .01

      for(int day=1;day<=20;day++){
         amount=principal*Math.pow(1 + rate, day);
         System.out.println(day + "   "+ amount);
      }
   }
}