import java.util.ArrayList ;

/**
   A purse holds a collection of coins.
*/
public class Purse
{
   // instance var is an ArrayList that will store Coin objects
   private ArrayList coins ;

   /**
      Constructs an empty purse.
   */
   public Purse()
   {
      coins = new ArrayList() ;
   }

   /**
      Add a coin to the purse.
      @param aCoin the coin to add
   */
   public void add(Coin aCoin)
   {
      coins.add(aCoin) ;	// calls ArrayList method add
   }

   /**
      Get the total value of the coins in the purse.
      @return the sum of all coin values
   */
   public double getTotal()
   {
      double total = 0;
      for (int i = 0; i < coins.size() ; i++)
      {
         Coin aCoin = (Coin)coins.get(i) ;	  // calls ArrayList method get
         total = total + aCoin.getValue() ;   // calls Coin method getValue      
      }
      return total ;
   }
}