find(method would return an item with specified key valueas we've seen when find(is list method replace(method could replace items that had certain key values with other items because it' singly linked listyou can only iterate along it in the forward direction if doubly linked list were usedyou could go either wayallowing operations such as deletion from the end of the listjust as with noniterator this would probably be convenience in some applications summary linked list consists of one linkedlist object and number of link objects the linkedlist object contains referenceoften called firstto the first link in the list each link object contains data and referenceoften called nextto the next link in the list next value of null signals the end of the list inserting an item at the beginning of linked list involves changing the new link' next field to point to the old first linkand changing first to point to the new item deleting an item at the beginning of list involves setting first to point to first next to traverse linked listyou start at firstthen go from link to linkusing each link' next field to find the next link link with specified key value can be found by traversing the list once foundan item can be displayeddeletedor operated on in other ways new link can be inserted before or after link with specified key valuefollowing traversal to find this link double-ended list maintains pointer to the last link in the listoften called lastas well as to the first double-ended list allows insertion at the end of the list an abstract data type (adtis data-storage class considered without reference to its implementation stacks and queues are adts they can be implemented using either arrays or linked lists in sorted linked listthe links are arranged in order of ascending (or sometimes descendingkey value insertion in sorted list takes (ntime because the correct insertion point must be found deletion of the smallest link takes ( time in doubly linked listeach link contains reference to the previous link as well as the next link