changxi wu

  public int howManyBooksDidThisAuthorWrite(String authorLastName)   {       int counter = 0;       for(int i = 0; i < inventory.length; i++ )        {            if(inventory[i].getLastName().equalsIgnoreCase(authorLastName))            {                counter++;            }        }        return counter;   }

Recaip Sanli wrote:So I need to touch elements of Photograph object array, but I can't. I entered hard value of 1 to touch them there's still an error:

Album.java:17: error: bad operand types for binary operator '+'
           priceResult = photos[1] + priceResult;
                                   ^
 first type:  Photograph
 second type: double
1 error

Should be like this. there is only one array. And photos[1] is Photograph, you should get the price by calling the instance method.

for(int i=0;i<photos.length;i++){
    priceResult = photos[i].getPrice() + priceResult;
}