As usual, let's start by looking at abstractions first so we have this iterator interface, which contains
the prototypes for methods that will contain the algorithm for traversing our container and of course,
the container interface here, which has a method that returns and iterator.
So let's see the classes that implement those those interfaces.
So the employee directory will implement the container.
The names of the employees will be stored in a list which will be given in the constructor of the employee
directory object.
And as you may have guessed, get iterator will return a new name iterator to us.
The name Iterator will use the composition technique to store the employee directory to have a reference
to the employee directory.
And these two methods will create the means for traversing and retrieving objects from inside the container.
So the first one, the next method will return.
True, as long as the employee directory is is bigger than the index, otherwise it will return false
and the next, as long as the house next will return.
True, then they are the object that is stored at that specific index will be returned to to us, will
be returned by this method.
Let's see how the client looks like.
So basically here we define a new list of employees with names or employees and we create an employee
directory based on this list, as you can see here.
And this is how the for loop looks like.
So we basically create an iterator based on the get the iterator method from the employee directory.
And we use the next method here to to traverse the container.
This this out you should print all the names of the employees using the next method, which like we've
seen, it's returning the objects that sit inside the container.
So let's see this in action.
Let's run this quickly.
And as you can see, we get the names here for all of the employees that are stored inside the employee
directory.
That's it.
For for this matter, you can download the code that we've used in this example from from the video
itself, from the video attachments section.
You can start playing with it so that you will understand it better.
And like I said, this is not a very complicated design pattern.
It's it is something that is offered by the Java API through the Iterator interface.
So it's nothing new, but it's a very, very good pattern to implement whenever you want to, to traverse
a custom data structure.
So this is the best use case for this design pattern.
So that's it.
Join me in the next video.
We are going to discuss about the mediator, Patrick.