List: Way to organize data.
List v.s. Array:
- List is 1-indexed (in this class).
- Array has limits.
- e.g., adding/removing from the middle
Example: Demonstrating how data shifts in a list
list.add(1, "Amy"); list.add(2, "Elias"); list.add(2, "Bob"); list.add(3, "Drew");
- Aaron
- Amy
- Elias
- Bob
- Drew
| Pseudocode | Description |
|---|---|
add(newEntry) | Add an item to the end of the list |
add(newPosition, newEntry) | Add an item anywhere in the list |
remove(givenPosition) | Remove an item anywhere in the list |
clear() | Remove all entries from the list |
replace(givenPosition, newEntry) | Replace an element at an index |
getEntry(givenPosition) | Get the entry at a position |
toArray() | Return list as an array |
contains(anEntry) | Returns whether the list contains an entry |
getLength() | Returns number of items in the list |
isEmpty() | Returns whether list is empty |
Example: Interface
public interface ListInterface<T> { void add(T newEntry) void add(int newPosition, T newEntry) T remove(int givenPosition) void clear() T replace(int givenPosition, T newEntry) T getEntry(int givenPosition) T[] toArray() boolean contains(T anEntry) int getLength() boolean isEmpty() }
Listvoid add(int index, T newEntry);
T remove(int index);
void clear();
T set (int index, T anEntry);
T get (int index);
boolean contains(Object anEntry);
int size();
boolean isEmpty();Note: If you implement the iterator as a separate class rather than an inner-class, you need to finagle with the list’s methods.
Inner-Class Iterator
public interface ListInterface<T> extends Iterable<T>public Iterator<T> iterator() {
// return the private iterator
}
private class IteratorForLinkedList implements Iterator<T> {
private Node nextNode;
private IteratorForLinkedList() {
nextNode = head;
}
//
public T next
}