Head First Design Patterns, 2nd Edition

Chapter 9. Well-Managed Collections: The Iterator and Composite Patterns

There are lots of ways to stuff objects into a collection. Put them into an Array, a Stack, a List, a hash map—take your pick. Each has its own advantages and tradeoffs. But at some point your clients are going to want to iterate over those objects, and when they do, are you going to show them your implementation? We certainly hope not! That just wouldn’t be professional. Well, you don’t have to risk your career; in this chapter you’re going to see how you can allow your clients to iterate through your objects without ever getting a peek at how you store your objects. You’re also going to learn how to create some super collections of objects that can leap over some impressive data structures in a single bound. And if that’s not enough, you’re also going to learn a thing or two about object responsibility.

Breaking News: Objectville Diner and Objectville Pancake House Merge

That’s great news! Now we can get those delicious pancake breakfasts at the Pancake House and those yummy lunches at the Diner all in one place. But there seems to be a slight problem...

Check out the Menu Items

At least Lou and Mel agree on the implementation of the MenuItems. Let’s check out the items on each menu, and also take ...