A Bag Implementation That Links Data - Data Structures and Abstractions with Java - page 81

11.

private Node getReferenceTo(T anEntry)
{

boolean found = false ;
Node currentNode = firstNode;
int counter = 0;
while (!found && (counter < numberOfEntries))
{

if (anEntry.equals(currentNode.data))
found = true ;
else
{

currentNode = currentNode.next;
counter++;
} // end if
} // end while
return currentNode;
} // end getReferenceTo

12.

The original definition of getReferenceTo ensures that currentNode is not null , and thus avoids a
NullPointerException .

13.

The effort expended by each of these two methods is about the same. Each method calls a private method
that searches for the desired entry. In LinkedBag , contains calls getReferenceTo , which searches at most
numberOfEntries nodes for the desired entry. In ResizableArrayBag , contains calls getIndexOf , which
searches at most numberOfEntries array elements for the desired entry. The next chapter will discuss these
methods and analyze their time requirements in more detail.