proj/proj1a/LinkedListDeque.java
public PlaceholderType removeFirst() {

        if (size == 0) {
            // no such item exists, return null
            return null;
        } else {
            // remove first item and return that item
            PlaceholderType firstItem = sentinel.next.item;
            sentinel.next.next.prev = sentinel;
            sentinel.next = sentinel.next.next;
            size -= 1;

            return firstItem;
        }

    }
/**  Removes and returns the item at the front of the deque.
     *   If no such item exists, returns null.
     *
     *   Args:
     *       None
     *
     *   Returns:
     *       First item in Linked-List-Deque or null
     * */
Removes and returns the item at the front of the deque.
If no such item exists, returns null.

None

First item in Linked-List-Deque or null
Removes and returns the item at the front of the deque . If no such item exists returns null . None First item in Linked - List - Deque or null
public PlaceholderType removeFirst() {
        if (size == 0) {
            return null;
        } else {
            PlaceholderType firstItem = sentinel.next.item;
            sentinel.next.next.prev = sentinel;
            sentinel.next = sentinel.next.next;
            size -= 1;
            return firstItem;
        }
    }
public PlaceholderType removeFirst ( ) { if ( size == 0 ) { return null ; } else { PlaceholderType firstItem = sentinel . next . item ; sentinel . next . next . prev = sentinel ; sentinel . next = sentinel . next . next ; size -= 1 ; return firstItem ; } }
Removes and returns the item at the front of the deque.
Removes and returns the item at the front of the deque .
// no such item exists, return null // remove first item and return that item