1. Linked Lists
Visual Basic 6.0

2. ADTs Data abstraction asks:
what you can do to a collection of data …apart from how you do it.
Ex: Pop Machine
Insert Money – Push button
Expect what?
What does ADT stand for?
Do you really care how the machine works? No you just want your soda!

3. What is a node?
Mathematics Definition: The point at which a continuous curve crosses itself.
Astronomy Definition: Either of two points at which the orbit of a satellite intersects the orbital plane of a planet
Others?
Ask students what the two questions they would have to ask would be if they were to create a CNode class?

4. Our Definition…
Node: a object which stores information and links to other nodes
What it looks like:

5. What Nodes “Have” Data part “Pointer” part
Disclaimer: “Pointers” truly do not exist in Visual Basic. They are actually called references (which “refer” to memory locations) However, for the sake visually representing a linked list, it is easier to “refer” to a reference as a pointer. Got it? If not, I will provide more “reference” material! Ugh! : )

6. What Nodes “Do” Store Data Show Data “Link to” other nodes
Tell who they are “linked to”

7. The Node Black Box View Data (let property) Data (get property)
NextNode (let property)
Refer back to black box created for fraction program
NextNode (get property)

8. The Node Open Black Box Self referential declaration (Node) myNext
(Integer) myData
Data (let property)
Data (get property)
NextNode (let property)
***Self referential declaration – reference to a variable of its own kind Why can we get away with this ?? Because its just a reference not an actual object
NextNode (get property)

9. Work Time on Nodes Group Work in worksheets. Link nodes together.
Node reference that traverses the list
Why is this better than the array?
One way street.

10. We are going to the store…
What do we need?
Well before we go to the store we need to make a list…

11. Shopping List… What do we need from the store? Milk Eggs Butter Apples
Bread
Others?
Why not an array? Contiguous memory allocation.