listing continued public link(int iddouble dd/constructor idata id/initialize data ddata dd/('nextis automatically /set to null/public void displaylink(/display ourself system out print("{idata "ddata "")/end class link ///////////////////////////////////////////////////////////////class linklist private link first/ref to first link on list /public linklist(/constructor first null/no items on list yet /public boolean isempty(/true if list is empty return (first==null)//insert at start of list public void insertfirst(int iddouble dd/make new link link newlink new link(iddd)newlink next first/newlink --old first first newlink/first --newlink /public link deletefirst(/delete first item /(assumes list not emptylink temp first/save reference to link first first next/delete itfirst-->old next return temp/return deleted link