Once youre comfortable with the code, you have the task:

void setEntry(int pos, const ItemType& item) 

Replace item at position pos in the list with the new parameter item. Throw the invalid_argument exception if pos < 1 or pos > getLength().

Here is the code:

#include  #include  #include  using namespace std; template class List { private: static const int CHUNK_SIZE=100; ItemType *list; int numItems; int maxItems; public: // default constructor and destructor List() { numItems = 0; maxItems = CHUNK_SIZE; list = new ItemType[CHUNK_SIZE]; } ~List() { delete [] list; } // list member functions bool isEmpty() const { return numItems==0; } int getLength() const { return numItems; } bool insert(int pos, const ItemType& item); bool remove(int pos); // clear the list // clear can simply set numItems to zero. The array list may still contain // items already inserted into the list, but since numItems is zero, there // isn't any way to get at them using getEntry() or setEntry() void clear() { numItems = 0; } // return entry at postion pos // throw invalid_argument if pos<1 or pos>getLength() ItemType getEntry(int pos) const; // set entry at postion pos to item // throw invalid_argument if pos<1 or pos>getLength() void setEntry(int pos, const ItemType& item); }; template bool List::insert(int pos, const ItemType& item) { bool canAdd; canAdd = ((pos > 0) && (pos <= numItems + 1) && (numItems < maxItems)); if (canAdd) { // first, we have to move everything after our insertion point over one // position to make room for our new item. start at the back of the list. // don't forget arrays start at postion zero and our list ADT starts at // position 1. for(int i=numItems; i>=pos; i--) list[i] = list[i-1]; // now put our item at position pos-1 list[pos-1] = item; numItems++; } return canAdd; } template ItemType List::getEntry(int pos) const { if(pos<1 || pos>getLength()) { throw invalid_argument("ERROR: getEntry() using invalid position"); } return list[pos-1]; } // TODO: add implementations for setEntry() and remove() functions // Utility function to input a track number with some input checking // to make sure it's a number int getTrack() { bool inputCheck; int trackNumber; do { inputCheck = true; cout << "Please enter the track number you'd like to view: "; if (!(cin >> trackNumber)) { cout << "Please enter numbers only. "; cin.clear(); cin.ignore(10000,' '); inputCheck = false; } } while (!inputCheck); return trackNumber; } int main() { List songs; char goAgain = 'y'; int trackNumber; string trackName; // Insert some songs into our list songs.insert(1, "One More Saturday Night"); songs.insert(1, "Friday I'm in Love"); songs.insert(3, "Sunday Morning Coming Down"); songs.insert(1, "California Love"); cout << "Welcome! There are " << songs.getLength() << " tracks. "; while (goAgain!='n') { trackNumber = getTrack(); try { trackName = songs.getEntry(trackNumber); } catch (invalid_argument arg) { cout << arg.what() << endl; trackName = "No Track"; } cout << "Your track name is " << trackName << endl; cout << "Go again? (y/n) "; cin >> goAgain; } cout << "Rock on! "; return 0; }